DAMASK_EICMD/code/lattice.f90

! Copyright 2011-13 Max-Planck-Institut für Eisenforschung GmbH
!
! This file is part of DAMASK,
! the Düsseldorf Advanced MAterial Simulation Kit.
!
! DAMASK is free software: you can redistribute it and/or modify
! it under the terms of the GNU General Public License as published by
! the Free Software Foundation, either version 3 of the License, or
! (at your option) any later version.
!
! DAMASK is distributed in the hope that it will be useful,
! but WITHOUT ANY WARRANTY; without even the implied warranty of
! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
! GNU General Public License for more details.
!
! You should have received a copy of the GNU General Public License
! along with DAMASK. If not, see <http://www.gnu.org/licenses/>.
!
!--------------------------------------------------------------------------------------------------
! $Id$
!--------------------------------------------------------------------------------------------------
!> @author Franz Roters, Max-Planck-Institut für Eisenforschung GmbH
!> @author Philip Eisenlohr, Max-Planck-Institut für Eisenforschung GmbH
!> @author Pratheek Shanthraj, Max-Planck-Institut für Eisenforschung GmbH
!> @brief  defines lattice structure definitions, slip and twin system definitions, Schimd matrix
!>         calculation and non-Schmid behavior
!--------------------------------------------------------------------------------------------------
module lattice
 use prec, only: &
   pReal, &
   pInt

 implicit none
 private
 integer(pInt), parameter, public :: &
   lattice_maxNslipFamily  =  6_pInt, &                                                             !< max # of slip system families over lattice structures
   lattice_maxNtwinFamily  =  4_pInt, &                                                             !< max # of twin system families over lattice structures
   lattice_maxNslip        = 33_pInt, &                                                             !< max # of slip systems over lattice structures
   lattice_maxNtwin        = 24_pInt, &                                                             !< max # of twin systems over lattice structures
   lattice_maxNinteraction = 42_pInt, &                                                             !< max # of interaction types (in hardening matrix part)
   lattice_maxNonSchmid    = 6_pInt                                                                 !< max # of non schmid contributions over lattice structures
 
 integer(pInt), allocatable, dimension(:,:), protected, public :: &
   lattice_NslipSystem, &                                                                           !< total # of slip systems in each family
   lattice_NtwinSystem                                                                              !< total # of twin systems in each family

 integer(pInt), allocatable, dimension(:,:,:), protected, public :: &
   lattice_interactionSlipSlip, &                                                                   !< Slip--slip interaction type 
   lattice_interactionSlipTwin, &                                                                   !< Slip--twin interaction type 
   lattice_interactionTwinSlip, &                                                                   !< Twin--slip interaction type 
   lattice_interactionTwinTwin                                                                      !< Twin--twin interaction type 


 real(pReal), allocatable, dimension(:,:,:,:), protected, public :: &
   lattice_Sslip_v, &
   lattice_Sslip                                                                                    !< Schmid matrices, normal, shear direction and d x n of slip systems                                          
  
 real(pReal), allocatable, dimension(:,:,:), protected, public :: &
   lattice_sn, &
   lattice_sd, &
   lattice_st

! rotation and Schmid matrices, normal, shear direction and d x n of twin systems
 real(pReal), allocatable, dimension(:,:,:,:), protected, public  :: &
   lattice_Stwin, &
   lattice_Qtwin

 real(pReal), allocatable, dimension(:,:,:), protected, public :: &
   lattice_Stwin_v, &
   lattice_tn, &
   lattice_td, &
   lattice_tt

 real(pReal), allocatable, dimension(:,:), protected, public :: &
   lattice_shearTwin                                                                                !< characteristic twin shear

 integer(pInt), private :: &
   lattice_Nhexagonal, &                                                                            !< total # of hexagonal lattice structure (from tag CoverA_ratio)
   lattice_Nstructure                                                                               !< total # of lattice structures (1: fcc,2: bcc,3+: hexagonal)

 integer(pInt), dimension(:,:), pointer, private :: &
   interactionSlipSlip, &
   interactionSlipTwin, &
   interactionTwinSlip, &
   interactionTwinTwin
   
 integer(pInt), allocatable, dimension(:), protected, public :: &
   NnonSchmid                                                                                       !< total # of non-Schmid contributions for each structure

!--------------------------------------------------------------------------------------------------
! fcc (1)
 integer(pInt), dimension(lattice_maxNslipFamily), parameter, public :: & 
   lattice_fcc_NslipSystem = int([12, 0, 0, 0, 0, 0],pInt)                                          !< total # of slip systems per family for fcc
   
 integer(pInt), dimension(lattice_maxNtwinFamily), parameter, public :: &
   lattice_fcc_NtwinSystem = int([12, 0, 0, 0],pInt)                                                !< total # of twin systems per family for fcc
   
 integer(pInt), parameter, private  :: &
   lattice_fcc_Nslip = 12_pInt, & ! sum(lattice_fcc_NslipSystem), &                                 !< total # of slip systems for fcc
   lattice_fcc_Ntwin = 12_pInt    ! sum(lattice_fcc_NtwinSystem)                                    !< total # of twin systems for fcc
 
 integer(pInt), private :: &
   lattice_fcc_Nstructure = 0_pInt

 real(pReal), dimension(3+3,lattice_fcc_Nslip), parameter, private :: &
   lattice_fcc_systemSlip = reshape(real([&
      0, 1,-1,     1, 1, 1, &
     -1, 0, 1,     1, 1, 1, &
      1,-1, 0,     1, 1, 1, &
      0,-1,-1,    -1,-1, 1, &
      1, 0, 1,    -1,-1, 1, &
     -1, 1, 0,    -1,-1, 1, &
      0,-1, 1,     1,-1,-1, &
     -1, 0,-1,     1,-1,-1, &
      1, 1, 0,     1,-1,-1, &
      0, 1, 1,    -1, 1,-1, &
      1, 0,-1,    -1, 1,-1, &
     -1,-1, 0,    -1, 1,-1  &
     ],pReal),[ 3_pInt + 3_pInt,lattice_fcc_Nslip])                                                 !< Slip system <110>{111} directions. Sorted according to Eisenlohr & Hantcherli

 real(pReal), dimension(3+3,lattice_fcc_Ntwin), parameter, private :: &
   lattice_fcc_systemTwin = reshape(real( [&
     -2, 1, 1,     1, 1, 1, &
      1,-2, 1,     1, 1, 1, &
      1, 1,-2,     1, 1, 1, &
      2,-1, 1,    -1,-1, 1, &
     -1, 2, 1,    -1,-1, 1, &
     -1,-1,-2,    -1,-1, 1, &
     -2,-1,-1,     1,-1,-1, &
      1, 2,-1,     1,-1,-1, &
      1,-1, 2,     1,-1,-1, &
      2, 1,-1,    -1, 1,-1, &
     -1,-2,-1,    -1, 1,-1, &
     -1, 1, 2,    -1, 1,-1  &
     ],pReal),[ 3_pInt + 3_pInt ,lattice_fcc_Ntwin])                                                !< Twin system <112>{111} directions. Sorted according to Eisenlohr & Hantcherli

 real(pReal), dimension(lattice_fcc_Ntwin), parameter, private :: &
   lattice_fcc_shearTwin = reshape([&
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal  &
     ],[lattice_fcc_Ntwin])                                                                         !< Twin system <112>{111} ??? Sorted according to Eisenlohr & Hantcherli

 integer(pInt), dimension(2_pInt,lattice_fcc_Ntwin), parameter, public :: &
   lattice_fcc_corellationTwinSlip = reshape(int( [&
     2,3, &
     1,3, &
     1,2, &
     5,6, &
     4,6, &
     4,5, &
     8,9, &
     7,9, &
     7,8, &
     11,12, &
     10,12, &
     10,11 &
     ],pInt),[2_pInt,lattice_fcc_Ntwin])

 integer(pInt), dimension(lattice_fcc_Nslip,lattice_fcc_Nslip), target, public :: &
   lattice_fcc_interactionSlipSlip = reshape(int( [&
     1,2,2,4,6,5,3,5,5,4,5,6, &  ! ---> slip
     2,1,2,6,4,5,5,4,6,5,3,5, &  ! |
     2,2,1,5,5,3,5,6,4,6,5,4, &  ! |
     4,6,5,1,2,2,4,5,6,3,5,5, &  ! v slip
     6,4,5,2,1,2,5,3,5,5,4,6, &
     5,5,3,2,2,1,6,5,4,5,6,4, &
     3,5,5,4,5,6,1,2,2,4,6,5, &
     5,4,6,5,3,5,2,1,2,6,4,5, &
     5,6,4,6,5,4,2,2,1,5,5,3, &
     4,5,6,3,5,5,4,6,5,1,2,2, &
     5,3,5,5,4,6,6,4,5,2,1,2, &
     6,5,4,5,6,4,5,5,3,2,2,1  &
     ],pInt),[lattice_fcc_Nslip,lattice_fcc_Nslip],order=[2,1])                                     !< Slip--slip interaction types for fcc
                                                                                                    !< 1: self interaction
                                                                                                    !< 2: coplanar interaction
                                                                                                    !< 3: collinear interaction
                                                                                                    !< 4: Hirth locks
                                                                                                    !< 5: glissile junctions
                                                                                                    !< 6: Lomer locks
 integer(pInt), dimension(lattice_fcc_Nslip,lattice_fcc_Ntwin), target, public :: &
   lattice_fcc_interactionSlipTwin = reshape(int( [&
     1,1,1,3,3,3,2,2,2,3,3,3, & ! ---> twin
     1,1,1,3,3,3,3,3,3,2,2,2, & ! |
     1,1,1,2,2,2,3,3,3,3,3,3, & ! |
     3,3,3,1,1,1,3,3,3,2,2,2, & ! v slip
     3,3,3,1,1,1,2,2,2,3,3,3, &
     2,2,2,1,1,1,3,3,3,3,3,3, &
     2,2,2,3,3,3,1,1,1,3,3,3, &
     3,3,3,2,2,2,1,1,1,3,3,3, &
     3,3,3,3,3,3,1,1,1,2,2,2, &
     3,3,3,2,2,2,3,3,3,1,1,1, &
     2,2,2,3,3,3,3,3,3,1,1,1, &
     3,3,3,3,3,3,2,2,2,1,1,1  &
     ],pInt),[lattice_fcc_Nslip,lattice_fcc_Ntwin],order=[2,1])                                     !< Slip--twin interaction types for fcc
                                                                                                    !< 1: coplanar interaction
                                                                                                    !< 2: screw trace between slip system and twin habit plane (easy cross slip)
                                                                                                    !< 3: other interaction
 integer(pInt), dimension(lattice_fcc_Ntwin,lattice_fcc_Nslip), target, public :: &
   lattice_fcc_interactionTwinSlip = 0_pInt                                                         !< Twin--Slip interaction types for fcc

 integer(pInt), dimension(lattice_fcc_Ntwin,lattice_fcc_Ntwin), target, public :: &
   lattice_fcc_interactionTwinTwin = reshape(int( [&
     1,1,1,2,2,2,2,2,2,2,2,2, &  ! ---> twin
     1,1,1,2,2,2,2,2,2,2,2,2, &  ! |
     1,1,1,2,2,2,2,2,2,2,2,2, &  ! |
     2,2,2,1,1,1,2,2,2,2,2,2, &  ! v twin
     2,2,2,1,1,1,2,2,2,2,2,2, &
     2,2,2,1,1,1,2,2,2,2,2,2, &
     2,2,2,2,2,2,1,1,1,2,2,2, &
     2,2,2,2,2,2,1,1,1,2,2,2, &
     2,2,2,2,2,2,1,1,1,2,2,2, &
     2,2,2,2,2,2,2,2,2,1,1,1, &
     2,2,2,2,2,2,2,2,2,1,1,1, &
     2,2,2,2,2,2,2,2,2,1,1,1  &
     ],pInt),[lattice_fcc_Ntwin,lattice_fcc_Ntwin],order=[2,1])                                     !< Twin--twin interaction types for fcc
     
 integer(pInt), parameter, private :: NnonSchmid_fcc = 0_pInt                                       !< total # of non-Schmid contributions for fcc
 
 real(pReal), dimension(3,3,2,NnonSchmid_fcc,lattice_fcc_Nslip), parameter, private :: &
   lattice_nonSchmid_fcc = 0.0_pReal ! reshape([],[3,3,2,NnonSchmid_fcc,lattice_fcc_Nslip])         !< Tensor for each non-Schmid contribution for fcc
 
 
!--------------------------------------------------------------------------------------------------
! bcc (2)
 integer(pInt), dimension(lattice_maxNslipFamily), parameter, public :: &
   lattice_bcc_NslipSystem = int([ 12, 12, 0, 0, 0, 0], pInt)                                       !< total # of slip systems per family for bcc
   
 integer(pInt), dimension(lattice_maxNtwinFamily), parameter, public :: &
   lattice_bcc_NtwinSystem = int([ 12, 0, 0, 0], pInt)                                              !< total # of twin systems per family for bcc
   
 integer(pInt), parameter, private  :: &
   lattice_bcc_Nslip = 24_pInt, & ! sum(lattice_bcc_NslipSystem), &                                 !< total # of slip systems for bcc
   lattice_bcc_Ntwin = 12_pInt    ! sum(lattice_bcc_NtwinSystem)                                    !< total # of twin systems for bcc
   
 integer(pInt), private :: &
   lattice_bcc_Nstructure = 0_pInt

 real(pReal), dimension(3+3,lattice_bcc_Nslip), parameter, private :: &
   lattice_bcc_systemSlip = reshape(real([&
    ! Slip system <111>{110} 
      1,-1, 1,     0, 1, 1, &
     -1,-1, 1,     0, 1, 1, &
      1, 1, 1,     0,-1, 1, &
     -1, 1, 1,     0,-1, 1, &
     -1, 1, 1,     1, 0, 1, &
     -1,-1, 1,     1, 0, 1, &
      1, 1, 1,    -1, 0, 1, &
      1,-1, 1,    -1, 0, 1, &
     -1, 1, 1,     1, 1, 0, &
     -1, 1,-1,     1, 1, 0, &
      1, 1, 1,    -1, 1, 0, &
      1, 1,-1,    -1, 1, 0, &
    ! Slip system <111>{112}
     -1, 1, 1,     2, 1, 1, &
      1, 1, 1,    -2, 1, 1, &
      1, 1,-1,     2,-1, 1, &
      1,-1, 1,     2, 1,-1, &
      1,-1, 1,     1, 2, 1, &
      1, 1,-1,    -1, 2, 1, &
      1, 1, 1,     1,-2, 1, &
     -1, 1, 1,     1, 2,-1, &
      1, 1,-1,     1, 1, 2, &
      1,-1, 1,    -1, 1, 2, &
     -1, 1, 1,     1,-1, 2, &
      1, 1, 1,     1, 1,-2  &
   !  Slip system <111>{123}
   !  1, 1,-1,     1, 2, 3, &
   !  1,-1, 1,    -1, 2, 3, &
   ! -1, 1, 1,     1,-2, 3, &
   !  1, 1, 1,     1, 2,-3, &
   !  1,-1, 1,     1, 3, 2, &
   !  1, 1,-1,    -1, 3, 2, &
   !  1, 1, 1,     1,-3, 2, &
   ! -1, 1, 1,     1, 3,-2, &
   !  1, 1,-1,     2, 1, 3, &
   !  1,-1, 1,    -2, 1, 3, &
   ! -1, 1, 1,     2,-1, 3, &
   !  1, 1, 1,     2, 1,-3, &
   !  1,-1, 1,     2, 3, 1, &
   !  1, 1,-1,    -2, 3, 1, &
   !  1, 1, 1,     2,-3, 1, &
   ! -1, 1, 1,     2, 3,-1, &
   ! -1, 1, 1,     3, 1, 2, &
   !  1, 1, 1,    -3, 1, 2, &
   !  1, 1,-1,     3,-1, 2, &
   !  1,-1, 1,     3, 1,-2, &
   ! -1, 1, 1,     3, 2, 1, &
   !  1, 1, 1,    -3, 2, 1, &
   !  1, 1,-1,     3,-2, 1, &
   !  1,-1, 1,     3, 2,-1  &
     ],pReal),[ 3_pInt + 3_pInt ,lattice_bcc_Nslip])

 real(pReal), dimension(3+3,lattice_bcc_Ntwin), parameter, private :: &
   lattice_bcc_systemTwin = reshape(real([&
    ! Twin system <111>{112}
     -1, 1, 1,     2, 1, 1, &
      1, 1, 1,    -2, 1, 1, &
      1, 1,-1,     2,-1, 1, &
      1,-1, 1,     2, 1,-1, &
      1,-1, 1,     1, 2, 1, &
      1, 1,-1,    -1, 2, 1, &
      1, 1, 1,     1,-2, 1, &
     -1, 1, 1,     1, 2,-1, &
      1, 1,-1,     1, 1, 2, &
      1,-1, 1,    -1, 1, 2, &
     -1, 1, 1,     1,-1, 2, &
      1, 1, 1,     1, 1,-2  &
     ],pReal),[ 3_pInt + 3_pInt,lattice_bcc_Ntwin])

 real(pReal), dimension(lattice_bcc_Ntwin), parameter, private :: &
   lattice_bcc_shearTwin = reshape([&
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal, &
     0.7071067812_pReal  &
     ],[lattice_bcc_Ntwin])

 integer(pInt), dimension(lattice_bcc_Nslip,lattice_bcc_Nslip), target, public :: &
   lattice_bcc_interactionSlipSlip = reshape(int( [&
     1,3,6,6,5,4,4,2,4,2,5,4, 6,6,4,2,2,4,6,6,4,2,6,6, &  ! ---> slip  
     3,1,6,6,4,2,5,4,5,4,4,2, 6,6,2,4,4,2,6,6,2,4,6,6, &  ! |
     6,6,1,3,4,5,2,4,4,5,2,4, 4,2,6,6,6,6,2,4,6,6,4,2, &  ! |
     6,6,3,1,2,4,4,5,2,4,4,5, 2,4,6,6,6,6,4,2,6,6,2,4, &  ! v slip
     5,4,4,2,1,3,6,6,2,4,5,4, 2,6,4,6,6,4,6,2,4,6,2,6, &
     4,2,5,4,3,1,6,6,4,5,4,2, 4,6,2,6,6,2,6,4,2,6,4,6, &
     4,5,2,4,6,6,1,3,5,4,2,4, 6,2,6,4,4,6,2,6,6,4,6,2, &
     2,4,4,5,6,6,3,1,4,2,4,5, 6,4,6,2,2,6,4,6,6,2,6,4, &
     4,5,4,2,2,4,5,4,1,3,6,6, 2,6,6,4,4,6,6,2,6,4,2,6, &
     2,4,5,4,4,5,4,2,3,1,6,6, 4,6,6,2,2,6,6,4,6,2,4,6, &
     5,4,2,4,5,4,2,4,6,6,1,3, 6,2,4,6,6,4,2,6,4,6,6,2, &
     4,2,4,5,4,2,4,5,6,6,3,1, 6,4,2,6,6,2,4,6,2,6,6,4, &
     !
     6,6,4,2,2,4,6,6,2,4,6,6, 1,5,6,6,5,6,6,2,5,6,2,6, &
     6,6,2,4,6,6,2,4,6,6,2,4, 5,1,6,6,6,5,2,6,6,5,6,2, &
     4,2,6,6,4,2,6,6,6,6,4,2, 6,6,1,5,6,2,5,6,2,6,5,6, &
     2,4,6,6,6,6,4,2,4,2,6,6, 6,6,5,1,2,6,6,5,6,2,6,5, &
     2,4,6,6,6,6,4,2,4,2,6,6, 5,6,6,2,1,6,5,6,5,2,6,6, &
     4,2,6,6,4,2,6,6,6,6,4,2, 6,5,2,6,6,1,6,5,2,5,6,6, &
     6,6,2,4,6,6,2,4,6,6,2,4, 6,2,5,6,5,6,1,6,6,6,5,2, &
     6,6,4,2,2,4,6,6,2,4,6,6, 2,6,6,5,6,5,6,1,6,6,2,5, &
     4,2,6,6,4,2,6,6,6,6,4,2, 5,6,2,6,5,2,6,6,1,6,6,5, &
     2,4,6,6,6,6,4,2,4,2,6,6, 6,5,6,2,2,5,6,6,6,1,5,6, &
     6,6,4,2,2,4,6,6,2,4,6,6, 2,6,5,6,6,6,5,2,6,5,1,6, &
     6,6,2,4,6,6,2,4,6,6,2,4, 6,2,6,5,6,6,2,5,5,6,6,1  &
     ],pInt),[lattice_bcc_Nslip,lattice_bcc_Nslip],order=[2,1])                                     !< Slip--slip interaction types for bcc from Lee et al. Int J Plast 15 (1999) 625-645
                                                                                                    !< 1: self interaction
                                                                                                    !< 2: no interaction
                                                                                                    !< 3: coplanar interaction
                                                                                                    !< 4: glissile interaction
                                                                                                    !< 5: weak sessile interaction
                                                                                                    !< 6: strong sessile interaction
 integer(pInt), dimension(lattice_bcc_Nslip,lattice_bcc_Ntwin), target, public :: &
  lattice_bcc_interactionSlipTwin = reshape(int( [&
     3,3,3,2,2,3,3,3,3,2,3,3, &  ! ---> twin
     3,3,2,3,3,2,3,3,2,3,3,3, &  ! |
     3,2,3,3,3,3,2,3,3,3,3,2, &  ! |
     2,3,3,3,3,3,3,2,3,3,2,3, &  ! v slip 
     2,3,3,3,3,3,3,2,3,3,2,3, &
     3,3,2,3,3,2,3,3,2,3,3,3, &
     3,2,3,3,3,3,2,3,3,3,3,2, &
     3,3,3,2,2,3,3,3,3,2,3,3, &
     2,3,3,3,3,3,3,2,3,3,2,3, &
     3,3,3,2,2,3,3,3,3,2,3,3, &
     3,2,3,3,3,3,2,3,3,3,3,2, &
     3,3,2,3,3,2,3,3,2,3,3,3, &
     !
     1,3,3,3,3,3,3,2,3,3,2,3, &
     3,1,3,3,3,3,2,3,3,3,3,2, &
     3,3,1,3,3,2,3,3,2,3,3,3, &
     3,3,3,1,2,3,3,3,3,2,3,3, &
     3,3,3,2,1,3,3,3,3,2,3,3, &
     3,3,2,3,3,1,3,3,2,3,3,3, &
     3,2,3,3,3,3,1,3,3,3,3,2, &
     2,3,3,3,3,3,3,1,3,3,2,3, &
     3,3,2,3,3,2,3,3,1,3,3,3, &
     3,3,3,2,2,3,3,3,3,1,3,3, &
     2,3,3,3,3,3,3,2,3,3,1,3, &
     3,2,3,3,3,3,2,3,3,3,3,1  &
     ],pInt),[lattice_bcc_Nslip,lattice_bcc_Ntwin],order=[2,1])                                     !< Slip--twin interaction types for bcc
                                                                                                    !< 1: coplanar interaction
                                                                                                    !< 2: screw trace between slip system and twin habit plane (easy cross slip)
                                                                                                    !< 3: other interaction
 integer(pInt), dimension(lattice_bcc_Ntwin,lattice_bcc_Nslip), target, public :: &
   lattice_bcc_interactionTwinSlip = 0_pInt                                                         !< Twin--slip interaction types for bcc @todo not implemented yet

 integer(pInt), dimension(lattice_bcc_Ntwin,lattice_bcc_Ntwin), target, public :: &
   lattice_bcc_interactionTwinTwin = reshape(int( [&
     1,3,3,3,3,3,3,2,3,3,2,3, &  ! ---> twin
     3,1,3,3,3,3,2,3,3,3,3,2, &  ! |
     3,3,1,3,3,2,3,3,2,3,3,3, &  ! |
     3,3,3,1,2,3,3,3,3,2,3,3, &  ! v twin
     3,3,3,2,1,3,3,3,3,2,3,3, &
     3,3,2,3,3,1,3,3,2,3,3,3, &
     3,2,3,3,3,3,1,3,3,3,3,2, &
     2,3,3,3,3,3,3,1,3,3,2,3, &
     3,3,2,3,3,2,3,3,1,3,3,3, &
     3,3,3,2,2,3,3,3,3,1,3,3, &
     2,3,3,3,3,3,3,2,3,3,1,3, &
     3,2,3,3,3,3,2,3,3,3,3,1  &
     ],pInt),[lattice_bcc_Ntwin,lattice_bcc_Ntwin],order=[2,1])                                     !< Twin--twin interaction types for bcc
                                                                                                    !< 1: self interaction
                                                                                                    !< 2: collinear interaction
                                                                                                    !< 3: other interaction
 integer(pInt), parameter, private :: NnonSchmid_bcc = 0_pInt                                       !< # of non-Schmid contributions for bcc
 
 real(pReal), dimension(3,3,2,NnonSchmid_bcc,lattice_bcc_Nslip), parameter, private :: &
   lattice_nonSchmid_bcc = 0.0_pReal ! reshape([],[3,3,2,NnonSchmid_bcc,lattice_bcc_Nslip])         !< Tensor for each non-Schmid contribution for bcc

!--------------------------------------------------------------------------------------------------
! hex (3+)
 integer(pInt), dimension(lattice_maxNslipFamily), parameter, public :: &
   lattice_hex_NslipSystem = int([ 3, 3, 6, 12, 6, 3],pInt)                                         !< # of slip systems per family for hex
   
 integer(pInt), dimension(lattice_maxNtwinFamily), parameter, public :: &
   lattice_hex_NtwinSystem = int([ 6, 6, 6, 6],pInt)                                                !< # of slip systems per family for hex 
   
 integer(pInt), parameter , private :: &
   lattice_hex_Nslip = 33_pInt, & ! sum(lattice_hex_NslipSystem),                                   !< total # of slip systems for hex 
   lattice_hex_Ntwin = 24_pInt    ! sum(lattice_hex_NtwinSystem)                                    !< total # of twin systems for hex
   
 integer(pInt), private :: &
   lattice_hex_Nstructure = 0_pInt

 real(pReal), dimension(4+4,lattice_hex_Nslip), parameter, private :: &
   lattice_hex_systemSlip = reshape(real([&
    ! Basal systems <11.0>{00.1} (independent of c/a-ratio, Bravais notation (4 coordinate base))
      2, -1, -1,  0,     0,  0,  0,  1, &
     -1,  2, -1,  0,     0,  0,  0,  1, &
     -1, -1,  2,  0,     0,  0,  0,  1, &
    ! 1st type prismatic systems <11.0>{10.0}  (independent of c/a-ratio)
      2, -1, -1,  0,     0,  1, -1,  0, &
     -1,  2, -1,  0,    -1,  0,  1,  0, &
     -1, -1,  2,  0,     1, -1,  0,  0, &
    ! 2nd type prismatic systems <10.0>{11.0} -- a slip; plane normals independent of c/a-ratio
      0,  1,  -1, 0,     2, -1, -1,  0, &
     -1,  0,  1,  0,    -1,  2, -1,  0, &
      1, -1,  0,  0,    -1, -1,  2,  0,  &
    ! 1st type 1st order pyramidal systems <11.0>{-11.1} -- plane normals depend on the c/a-ratio
      2, -1, -1,  0,     0,  1, -1,  1, &
     -1,  2, -1,  0,    -1,  0,  1,  1, &
     -1, -1,  2,  0,     1, -1,  0,  1, &
      1,  1, -2,  0,    -1,  1,  0,  1, &
     -2,  1,  1,  0,     0, -1,  1,  1, &
      1, -2,  1,  0,     1,  0, -1,  1, &
    ! pyramidal system: c+a slip <11.3>{-10.1} -- plane normals depend on the c/a-ratio
      2, -1, -1,  3,    -1,  1,  0,  1, &
      1, -2,  1,  3,    -1,  1,  0,  1, &
     -1, -1,  2,  3,     1,  0, -1,  1, &
     -2,  1,  1,  3,     1,  0, -1,  1, &
     -1,  2, -1,  3,     0, -1,  1,  1, &
      1,  1, -2,  3,     0, -1,  1,  1, &
     -2,  1,  1,  3,     1, -1,  0,  1, &
     -1,  2, -1,  3,     1, -1,  0,  1, &
      1,  1, -2,  3,    -1,  0,  1,  1, &
      2, -1, -1,  3,    -1,  0,  1,  1, &
      1, -2,  1,  3,     0,  1, -1,  1, &
     -1, -1,  2,  3,     0,  1, -1,  1, &
    ! pyramidal system: c+a slip <11.3>{-1-1.2} -- as for hexagonal ice (Castelnau et al 1996, similar to twin system found below) 
      2, -1, -1,  3,    -2,  1,  1,  2, & ! sorted according to similar twin system
     -1,  2, -1,  3,     1, -2,  1,  2, & ! <11.3>{-1-1.2} shear = 2((c/a)^2-2)/(3 c/a)
     -1, -1,  2,  3,     1,  1, -2,  2, &
     -2,  1,  1,  3,     2, -1, -1,  2, &
      1, -2,  1,  3,    -1,  2, -1,  2, &
      1,  1, -2,  3,    -1, -1,  2,  2  &
     ],pReal),[ 4_pInt + 4_pInt,lattice_hex_Nslip])                                                 !< slip systems for hex sorted by A. Alankar & P. Eisenlohr

 real(pReal), dimension(4+4,lattice_hex_Ntwin), parameter, private :: &
   lattice_hex_systemTwin =  reshape(real([&
      1, -1,  0,  1,    -1,  1,  0,  2, & ! <-10.1>{10.2} shear = (3-(c/a)^2)/(sqrt(3) c/a)
     -1,  0,  1,  1,     1,  0, -1,  2, &
      0,  1, -1,  1,     0, -1,  1,  2, &
     -1,  1,  0,  1,     1, -1,  0,  2, &
      1,  0, -1,  1,    -1,  0,  1,  2, &
      0, -1,  1,  1,     0,  1, -1,  2, &
!
      2, -1, -1,  6,    -2,  1,  1,  1, & ! <11.6>{-1-1.1} shear = 1/(c/a)
     -1,  2, -1,  6,     1, -2,  1,  1, &
     -1, -1,  2,  6,     1,  1, -2,  1, &
     -2,  1,  1,  6,     2, -1, -1,  1, &
      1, -2,  1,  6,    -1,  2, -1,  1, &
      1,  1, -2,  6,    -1, -1,  2,  1, &
!
     -1,  1,  0, -2,    -1,  1,  0,  1,  & !! <10.-2>{10.1} shear = (4(c/a)^2-9)/(4 sqrt(3) c/a)
      1,  0, -1, -2,     1,  0, -1,  1, &
      0, -1,  1, -2,     0, -1,  1,  1, &
      1, -1,  0, -2,     1, -1,  0,  1, &
     -1,  0,  1, -2,    -1,  0,  1,  1, &
      0,  1, -1, -2,     0,  1, -1,  1, &
!
      2, -1, -1, -3,     2, -1, -1,  2, & ! <11.-3>{11.2} shear = 2((c/a)^2-2)/(3 c/a)
     -1,  2, -1, -3,    -1,  2, -1,  2, &
     -1, -1,  2, -3,    -1, -1,  2,  2, &
     -2,  1,  1, -3,    -2,  1,  1,  2, &
      1, -2,  1, -3,     1, -2,  1,  2, &
      1,  1, -2, -3,     1,  1, -2,  2  &
     ],pReal),[ 4_pInt + 4_pInt ,lattice_hex_Ntwin])                                                !< twin systems for hex, order follows Prof. Tom Bieler's scheme; but numbering in data was restarted from 1 

 integer(pInt), dimension(lattice_hex_Ntwin), parameter, private :: &
   lattice_hex_shearTwin = reshape(int( [&   ! indicator to formula further below
     1, &  ! <-10.1>{10.2}
     1, &
     1, &
     1, &
     1, &
     1, &
     2, &  ! <11.6>{-1-1.1}
     2, &
     2, &
     2, &
     2, &
     2, &
     3, &  ! <10.-2>{10.1}
     3, &
     3, &
     3, &
     3, &
     3, &
     4, &  ! <11.-3>{11.2}
     4, &
     4, &
     4, &
     4, &
     4  &
     ],pInt),[lattice_hex_Ntwin])
   
 integer(pInt), dimension(lattice_hex_Nslip,lattice_hex_Nslip), target, public :: &
   lattice_hex_interactionSlipSlip = reshape(int( [&
      1, 2, 2,   3, 3, 3,   7, 7, 7,  13,13,13,13,13,13,  21,21,21,21,21,21,21,21,21,21,21,21,  31,31,31,31,31,31, &  ! ---> slip
      2, 1, 2,   3, 3, 3,   7, 7, 7,  13,13,13,13,13,13,  21,21,21,21,21,21,21,21,21,21,21,21,  31,31,31,31,31,31, &  ! |
      2, 2, 1,   3, 3, 3,   7, 7, 7,  13,13,13,13,13,13,  21,21,21,21,21,21,21,21,21,21,21,21,  31,31,31,31,31,31, &  ! |
    !                                                                                                                   v slip
      6, 6, 6,   4, 5, 5,   8, 8, 8,  14,14,14,14,14,14,  22,22,22,22,22,22,22,22,22,22,22,22,  32,32,32,32,32,32, &
      6, 6, 6,   5, 4, 5,   8, 8, 8,  14,14,14,14,14,14,  22,22,22,22,22,22,22,22,22,22,22,22,  32,32,32,32,32,32, &
      6, 6, 6,   5, 5, 4,   8, 8, 8,  14,14,14,14,14,14,  22,22,22,22,22,22,22,22,22,22,22,22,  32,32,32,32,32,32, &
    !
     12,12,12,  11,11,11,   9,10,10,  15,15,15,15,15,15,  33,33,33,33,33,33,33,33,33,33,33,33,  33,33,33,33,33,33, &
     12,12,12,  11,11,11,  10, 9,10,  15,15,15,15,15,15,  33,33,33,33,33,33,33,33,33,33,33,33,  33,33,33,33,33,33, &
     12,12,12,  11,11,11,  10,10, 9,  15,15,15,15,15,15,  33,33,33,33,33,33,33,33,33,33,33,33,  33,33,33,33,33,33, &
    !
     20,20,20,  19,19,19,  18,18,18,  16,17,17,17,17,17,  24,24,24,24,24,24,24,24,24,24,24,24,  34,34,34,34,34,34, &
     20,20,20,  19,19,19,  18,18,18,  17,16,17,17,17,17,  24,24,24,24,24,24,24,24,24,24,24,24,  34,34,34,34,34,34, &
     20,20,20,  19,19,19,  18,18,18,  17,17,16,17,17,17,  24,24,24,24,24,24,24,24,24,24,24,24,  34,34,34,34,34,34, &
     20,20,20,  19,19,19,  18,18,18,  17,17,17,16,17,17,  24,24,24,24,24,24,24,24,24,24,24,24,  34,34,34,34,34,34, &
     20,20,20,  19,19,19,  18,18,18,  17,17,17,17,16,17,  24,24,24,24,24,24,24,24,24,24,24,24,  34,34,34,34,34,34, &
     20,20,20,  19,19,19,  18,18,18,  17,17,17,17,17,16,  24,24,24,24,24,24,24,24,24,24,24,24,  34,34,34,34,34,34, &
    !
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  25,26,26,26,26,26,26,26,26,26,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,25,26,26,26,26,26,26,26,26,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,25,26,26,26,26,26,26,26,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,26,25,26,26,26,26,26,26,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,26,26,25,26,26,26,26,26,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,26,26,26,25,26,26,26,26,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,26,26,26,26,25,26,26,26,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,26,26,26,26,26,25,26,26,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,26,26,26,26,26,26,25,26,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,26,26,26,26,26,26,26,25,26,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,26,26,26,26,26,26,26,26,25,26,  35,35,35,35,35,35, &
     30,30,30,  29,29,29,  28,28,28,  27,27,27,27,27,27,  26,26,26,26,26,26,26,26,26,26,26,25,  35,35,35,35,35,35, &
    !
     42,42,42,  41,41,41,  40,40,40,  39,39,39,39,39,39,  38,38,38,38,38,38,38,38,38,38,38,38,  36,37,37,37,37,37, &
     42,42,42,  41,41,41,  40,40,40,  39,39,39,39,39,39,  38,38,38,38,38,38,38,38,38,38,38,38,  37,36,37,37,37,37, &
     42,42,42,  41,41,41,  40,40,40,  39,39,39,39,39,39,  38,38,38,38,38,38,38,38,38,38,38,38,  37,37,36,37,37,37, &
     42,42,42,  41,41,41,  40,40,40,  39,39,39,39,39,39,  38,38,38,38,38,38,38,38,38,38,38,38,  37,37,37,36,37,37, &
     42,42,42,  41,41,41,  40,40,40,  39,39,39,39,39,39,  38,38,38,38,38,38,38,38,38,38,38,38,  37,37,37,37,36,37, &
     42,42,42,  41,41,41,  40,40,40,  39,39,39,39,39,39,  38,38,38,38,38,38,38,38,38,38,38,38,  37,37,37,37,37,36  &  
    !
           ],pInt),[lattice_hex_Nslip,lattice_hex_Nslip],order=[2,1])                                     !< Slip--slip interaction types for hex (32? in total)
  
 integer(pInt), dimension(lattice_hex_Nslip,lattice_hex_Ntwin), target, public :: &
   lattice_hex_interactionSlipTwin = reshape(int( [&
      1, 1, 1, 1, 1, 1,   2, 2, 2, 2, 2, 2,   3, 3, 3, 3, 3, 3,   4, 4, 4, 4, 4, 4, & ! --> twin
      1, 1, 1, 1, 1, 1,   2, 2, 2, 2, 2, 2,   3, 3, 3, 3, 3, 3,   4, 4, 4, 4, 4, 4, & ! |
      1, 1, 1, 1, 1, 1,   2, 2, 2, 2, 2, 2,   3, 3, 3, 3, 3, 3,   4, 4, 4, 4, 4, 4, & ! |
    !                                                                                   v
      5, 5, 5, 5, 5, 5,   6, 6, 6, 6, 6, 6,   7, 7, 7, 7, 7, 7,   8, 8, 8, 8, 8, 8, & ! slip
      5, 5, 5, 5, 5, 5,   6, 6, 6, 6, 6, 6,   7, 7, 7, 7, 7, 7,   8, 8, 8, 8, 8, 8, & 
      5, 5, 5, 5, 5, 5,   6, 6, 6, 6, 6, 6,   7, 7, 7, 7, 7, 7,   8, 8, 8, 8, 8, 8, &
    !
      9, 9, 9, 9, 9, 9,  10,10,10,10,10,10,  11,11,11,11,11,11,  12,12,12,12,12,12, &
      9, 9, 9, 9, 9, 9,  10,10,10,10,10,10,  11,11,11,11,11,11,  12,12,12,12,12,12, &
      9, 9, 9, 9, 9, 9,  10,10,10,10,10,10,  11,11,11,11,11,11,  12,12,12,12,12,12, &
    !
     13,13,13,13,13,13,  14,14,14,14,14,14,  15,15,15,15,15,15,  16,16,16,16,16,16, &
     13,13,13,13,13,13,  14,14,14,14,14,14,  15,15,15,15,15,15,  16,16,16,16,16,16, &
     13,13,13,13,13,13,  14,14,14,14,14,14,  15,15,15,15,15,15,  16,16,16,16,16,16, &
     13,13,13,13,13,13,  14,14,14,14,14,14,  15,15,15,15,15,15,  16,16,16,16,16,16, &
     13,13,13,13,13,13,  14,14,14,14,14,14,  15,15,15,15,15,15,  16,16,16,16,16,16, &
     13,13,13,13,13,13,  14,14,14,14,14,14,  15,15,15,15,15,15,  16,16,16,16,16,16, &
    !
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
     17,17,17,17,17,17,  18,18,18,18,18,18,  19,19,19,19,19,19,  20,20,20,20,20,20, &
    !
     21,21,21,21,21,21,  10,10,10,10,10,10,  23,23,23,23,23,23,  24,24,24,24,24,24, &
     21,21,21,21,21,21,  10,10,10,10,10,10,  23,23,23,23,23,23,  24,24,24,24,24,24, &
     21,21,21,21,21,21,  10,10,10,10,10,10,  23,23,23,23,23,23,  24,24,24,24,24,24, &
     21,21,21,21,21,21,  10,10,10,10,10,10,  23,23,23,23,23,23,  24,24,24,24,24,24, &
     21,21,21,21,21,21,  10,10,10,10,10,10,  23,23,23,23,23,23,  24,24,24,24,24,24, &
     21,21,21,21,21,21,  10,10,10,10,10,10,  23,23,23,23,23,23,  24,24,24,24,24,24  &
    !
     ],pInt),[lattice_hex_Nslip,lattice_hex_Ntwin],order=[2,1])                                     !< Slip--twin interaction types for hex (isotropic, 24 in total) 

 integer(pInt), dimension(lattice_hex_Ntwin,lattice_hex_Nslip), target, public :: &
   lattice_hex_interactionTwinSlip = reshape(int( [&
      1, 1, 1,   5, 5, 5,   9, 9, 9,  13,13,13,13,13,13,  17,17,17,17,17,17,17,17,17,17,17,17,  21,21,21,21,21,21, & ! --> slip
      1, 1, 1,   5, 5, 5,   9, 9, 9,  13,13,13,13,13,13,  17,17,17,17,17,17,17,17,17,17,17,17,  21,21,21,21,21,21, & ! |
      1, 1, 1,   5, 5, 5,   9, 9, 9,  13,13,13,13,13,13,  17,17,17,17,17,17,17,17,17,17,17,17,  21,21,21,21,21,21, & ! |
      1, 1, 1,   5, 5, 5,   9, 9, 9,  13,13,13,13,13,13,  17,17,17,17,17,17,17,17,17,17,17,17,  21,21,21,21,21,21, & ! v
      1, 1, 1,   5, 5, 5,   9, 9, 9,  13,13,13,13,13,13,  17,17,17,17,17,17,17,17,17,17,17,17,  21,21,21,21,21,21, & ! twin
      1, 1, 1,   5, 5, 5,   9, 9, 9,  13,13,13,13,13,13,  17,17,17,17,17,17,17,17,17,17,17,17,  21,21,21,21,21,21, &
    !
      2, 2, 2,   6, 6, 6,  10,10,10,  14,14,14,14,14,14,  18,18,18,18,18,18,18,18,18,18,18,18,  22,22,22,22,22,22, &
      2, 2, 2,   6, 6, 6,  10,10,10,  14,14,14,14,14,14,  18,18,18,18,18,18,18,18,18,18,18,18,  22,22,22,22,22,22, &
      2, 2, 2,   6, 6, 6,  10,10,10,  14,14,14,14,14,14,  18,18,18,18,18,18,18,18,18,18,18,18,  22,22,22,22,22,22, &
      2, 2, 2,   6, 6, 6,  10,10,10,  14,14,14,14,14,14,  18,18,18,18,18,18,18,18,18,18,18,18,  22,22,22,22,22,22, &
      2, 2, 2,   6, 6, 6,  10,10,10,  14,14,14,14,14,14,  18,18,18,18,18,18,18,18,18,18,18,18,  22,22,22,22,22,22, &
      2, 2, 2,   6, 6, 6,  10,10,10,  14,14,14,14,14,14,  18,18,18,18,18,18,18,18,18,18,18,18,  22,22,22,22,22,22, &
    !
      3, 3, 3,   7, 7, 7,  11,11,11,  15,15,15,15,15,15,  19,19,19,19,19,19,19,19,19,19,19,19,  23,23,23,23,23,23, &
      3, 3, 3,   7, 7, 7,  11,11,11,  15,15,15,15,15,15,  19,19,19,19,19,19,19,19,19,19,19,19,  23,23,23,23,23,23, &
      3, 3, 3,   7, 7, 7,  11,11,11,  15,15,15,15,15,15,  19,19,19,19,19,19,19,19,19,19,19,19,  23,23,23,23,23,23, &
      3, 3, 3,   7, 7, 7,  11,11,11,  15,15,15,15,15,15,  19,19,19,19,19,19,19,19,19,19,19,19,  23,23,23,23,23,23, &
      3, 3, 3,   7, 7, 7,  11,11,11,  15,15,15,15,15,15,  19,19,19,19,19,19,19,19,19,19,19,19,  23,23,23,23,23,23, &
      3, 3, 3,   7, 7, 7,  11,11,11,  15,15,15,15,15,15,  19,19,19,19,19,19,19,19,19,19,19,19,  23,23,23,23,23,23, &
    !
      4, 4, 4,   8, 8, 8,  12,12,12,  16,16,16,16,16,16,  20,20,20,20,20,20,20,20,20,20,20,20,  24,24,24,24,24,24, &
      4, 4, 4,   8, 8, 8,  12,12,12,  16,16,16,16,16,16,  20,20,20,20,20,20,20,20,20,20,20,20,  24,24,24,24,24,24, &
      4, 4, 4,   8, 8, 8,  12,12,12,  16,16,16,16,16,16,  20,20,20,20,20,20,20,20,20,20,20,20,  24,24,24,24,24,24, &
      4, 4, 4,   8, 8, 8,  12,12,12,  16,16,16,16,16,16,  20,20,20,20,20,20,20,20,20,20,20,20,  24,24,24,24,24,24, &
      4, 4, 4,   8, 8, 8,  12,12,12,  16,16,16,16,16,16,  20,20,20,20,20,20,20,20,20,20,20,20,  24,24,24,24,24,24, &
      4, 4, 4,   8, 8, 8,  12,12,12,  16,16,16,16,16,16,  20,20,20,20,20,20,20,20,20,20,20,20,  24,24,24,24,24,24  &
     ],pInt),[lattice_hex_Ntwin,lattice_hex_Nslip],order=[2,1])                                     !< Twin--twin interaction types for hex (isotropic, 20 in total)

 integer(pInt), dimension(lattice_hex_Ntwin,lattice_hex_Ntwin), target, public :: &
   lattice_hex_interactionTwinTwin = reshape(int( [&
      1, 2, 2, 2, 2, 2,   3, 3, 3, 3, 3, 3,   7, 7, 7, 7, 7, 7,  13,13,13,13,13,13, &  ! ---> twin
      2, 1, 2, 2, 2, 2,   3, 3, 3, 3, 3, 3,   7, 7, 7, 7, 7, 7,  13,13,13,13,13,13, &  ! |
      2, 2, 1, 2, 2, 2,   3, 3, 3, 3, 3, 3,   7, 7, 7, 7, 7, 7,  13,13,13,13,13,13, &  ! |
      2, 2, 2, 1, 2, 2,   3, 3, 3, 3, 3, 3,   7, 7, 7, 7, 7, 7,  13,13,13,13,13,13, &  ! v twin
      2, 2, 2, 2, 1, 2,   3, 3, 3, 3, 3, 3,   7, 7, 7, 7, 7, 7,  13,13,13,13,13,13, &
      2, 2, 2, 2, 2, 1,   3, 3, 3, 3, 3, 3,   7, 7, 7, 7, 7, 7,  13,13,13,13,13,13, &
    !
      6, 6, 6, 6, 6, 6,   4, 5, 5, 5, 5, 5,   8, 8, 8, 8, 8, 8,  14,14,14,14,14,14, &
      6, 6, 6, 6, 6, 6,   5, 4, 5, 5, 5, 5,   8, 8, 8, 8, 8, 8,  14,14,14,14,14,14, &
      6, 6, 6, 6, 6, 6,   5, 5, 4, 5, 5, 5,   8, 8, 8, 8, 8, 8,  14,14,14,14,14,14, &
      6, 6, 6, 6, 6, 6,   5, 5, 5, 4, 5, 5,   8, 8, 8, 8, 8, 8,  14,14,14,14,14,14, &
      6, 6, 6, 6, 6, 6,   5, 5, 5, 5, 4, 5,   8, 8, 8, 8, 8, 8,  14,14,14,14,14,14, &
      6, 6, 6, 6, 6, 6,   5, 5, 5, 5, 5, 4,   8, 8, 8, 8, 8, 8,  14,14,14,14,14,14, &
    !
     12,12,12,12,12,12,  11,11,11,11,11,11,   9,10,10,10,10,10,  15,15,15,15,15,15, &
     12,12,12,12,12,12,  11,11,11,11,11,11,  10, 9,10,10,10,10,  15,15,15,15,15,15, &
     12,12,12,12,12,12,  11,11,11,11,11,11,  10,10, 9,10,10,10,  15,15,15,15,15,15, &
     12,12,12,12,12,12,  11,11,11,11,11,11,  10,10,10, 9,10,10,  15,15,15,15,15,15, &
     12,12,12,12,12,12,  11,11,11,11,11,11,  10,10,10,10, 9,10,  15,15,15,15,15,15, &
     12,12,12,12,12,12,  11,11,11,11,11,11,  10,10,10,10,10, 9,  15,15,15,15,15,15, &
    !
     20,20,20,20,20,20,  19,19,19,19,19,19,  18,18,18,18,18,18,  16,17,17,17,17,17, &
     20,20,20,20,20,20,  19,19,19,19,19,19,  18,18,18,18,18,18,  17,16,17,17,17,17, &
     20,20,20,20,20,20,  19,19,19,19,19,19,  18,18,18,18,18,18,  17,17,16,17,17,17, &
     20,20,20,20,20,20,  19,19,19,19,19,19,  18,18,18,18,18,18,  17,17,17,16,17,17, &
     20,20,20,20,20,20,  19,19,19,19,19,19,  18,18,18,18,18,18,  17,17,17,17,16,17, &
     20,20,20,20,20,20,  19,19,19,19,19,19,  18,18,18,18,18,18,  17,17,17,17,17, 4  &
     ],pInt),[lattice_hex_Ntwin,lattice_hex_Ntwin],order=[2,1])                                     !< Twin--slip interaction types for hex (isotropic, 16 in total)
     
 integer(pInt), parameter, private :: NnonSchmid_hex = 0_pInt                                       !< # of non-Schmid contributions for hex
 
 real(pReal), dimension(3,3,2,NnonSchmid_hex,lattice_hex_Nslip), parameter, private :: &
   lattice_nonSchmid_hex = 0.0_pReal ! reshape([],[3,3,2,NnonSchmid_hex,lattice_hex_Nslip])         !< Tensor for each non-Schmid contribution for hex

 public :: &
  lattice_init, &
  lattice_initializeStructure, &
  lattice_symmetryType, &
  lattice_symmetrizeC66, &
  lattice_configNchunks

contains

!--------------------------------------------------------------------------------------------------
!> @brief Module initialization
!--------------------------------------------------------------------------------------------------
subroutine lattice_init
 use, intrinsic :: iso_fortran_env                                                                  ! to get compiler_version and compiler_options (at least for gfortran 4.6 at the moment)
 use IO, only: &
   IO_open_file,&
   IO_open_jobFile_stat, &
   IO_countSections, &
   IO_countTagInPart, &
   IO_error, &
   IO_timeStamp
 use material, only: &
   material_configfile, &
   material_localFileExt, &
   material_partPhase
 use debug, only: &
   debug_level, &
   debug_lattice, &
   debug_levelBasic

 implicit none
 integer(pInt), parameter :: fileunit = 200_pInt
 integer(pInt) :: Nsections

 write(6,'(/,a)') ' <<<+-  lattice init  -+>>>'
 write(6,'(a)')   ' $Id$'
 write(6,'(a15,a)')   ' Current time: ',IO_timeStamp()
#include "compilation_info.f90"

 if (.not. IO_open_jobFile_stat(fileunit,material_localFileExt)) then                               ! no local material configuration present...
   call IO_open_file(fileunit,material_configFile)                                                  ! ... open material.config file
 endif
 Nsections = IO_countSections(fileunit,material_partPhase)
 lattice_Nstructure = 2_pInt + sum(IO_countTagInPart(fileunit,material_partPhase,'covera_ratio',Nsections)) ! fcc + bcc + all hex
 close(fileunit)

 if (iand(debug_level(debug_lattice),debug_levelBasic) /= 0_pInt) then
   write(6,'(a16,1x,i5)')   ' # phases:',Nsections
   write(6,'(a16,1x,i5,/)') ' # structures:',lattice_Nstructure
 endif

 allocate(NnonSchmid(lattice_Nstructure));                         NnonSchmid = 0_pInt
 allocate(lattice_Sslip(3,3,lattice_maxNslip,lattice_Nstructure)); lattice_Sslip   = 0.0_pReal
 allocate(lattice_Sslip_v(6,1+2*lattice_maxNonSchmid,lattice_maxNslip,lattice_Nstructure)); lattice_Sslip_v = 0.0_pReal
 allocate(lattice_sd(3,lattice_maxNslip,lattice_Nstructure));      lattice_sd      = 0.0_pReal
 allocate(lattice_st(3,lattice_maxNslip,lattice_Nstructure));      lattice_st      = 0.0_pReal
 allocate(lattice_sn(3,lattice_maxNslip,lattice_Nstructure));      lattice_sn      = 0.0_pReal

 allocate(lattice_Qtwin(3,3,lattice_maxNtwin,lattice_Nstructure)); lattice_Qtwin   = 0.0_pReal
 allocate(lattice_Stwin(3,3,lattice_maxNtwin,lattice_Nstructure)); lattice_Stwin   = 0.0_pReal
 allocate(lattice_Stwin_v(6,lattice_maxNtwin,lattice_Nstructure)); lattice_Stwin_v = 0.0_pReal
 allocate(lattice_td(3,lattice_maxNtwin,lattice_Nstructure));      lattice_td      = 0.0_pReal
 allocate(lattice_tt(3,lattice_maxNtwin,lattice_Nstructure));      lattice_tt      = 0.0_pReal
 allocate(lattice_tn(3,lattice_maxNtwin,lattice_Nstructure));      lattice_tn      = 0.0_pReal

 allocate(lattice_shearTwin(lattice_maxNtwin,lattice_Nstructure)); lattice_shearTwin = 0.0_pReal

 allocate(lattice_NslipSystem(lattice_maxNslipFamily,lattice_Nstructure)); lattice_NslipSystem = 0_pInt
 allocate(lattice_NtwinSystem(lattice_maxNtwinFamily,lattice_Nstructure)); lattice_NtwinSystem = 0_pInt

 allocate(lattice_interactionSlipSlip(lattice_maxNslip,lattice_maxNslip,lattice_Nstructure))
          lattice_interactionSlipSlip = 0_pInt ! other:me
 allocate(lattice_interactionSlipTwin(lattice_maxNslip,lattice_maxNtwin,lattice_Nstructure))
          lattice_interactionSlipTwin = 0_pInt ! other:me
 allocate(lattice_interactionTwinSlip(lattice_maxNtwin,lattice_maxNslip,lattice_Nstructure))
          lattice_interactionTwinSlip = 0_pInt ! other:me
 allocate(lattice_interactionTwinTwin(lattice_maxNtwin,lattice_maxNtwin,lattice_Nstructure))
          lattice_interactionTwinTwin = 0_pInt ! other:me

end subroutine lattice_init


!--------------------------------------------------------------------------------------------------
!> @brief   Calculation of Schmid matrices, etc.
!--------------------------------------------------------------------------------------------------
integer(pInt) function lattice_initializeStructure(struct,CoverA)
 use math, only: &
   math_vectorproduct, &
   math_tensorproduct, &
   math_norm3, &
   math_trace33, &
   math_symmetric33, &
   math_Mandel33to6, &
   math_axisAngleToR, &
   INRAD
 use IO, only: &
   IO_error
 
 implicit none
 character(len=*) struct
 real(pReal) CoverA
 real(pReal), dimension(3,lattice_maxNslip) :: sd = 0.0_pReal, &
                                               sn = 0.0_pReal
 real(pReal), dimension(12,lattice_maxNonSchmid,lattice_maxNslip) :: sns = 0.0_pReal
 real(pReal), dimension(3,lattice_maxNtwin) :: td = 0.0_pReal, &
                                               tn = 0.0_pReal
 real(pReal), dimension(lattice_maxNtwin) ::   ts = 0.0_pReal
 integer(pInt), dimension(lattice_maxNslipFamily) :: myNslipSystem = 0_pInt
 integer(pInt), dimension(lattice_maxNtwinFamily) :: myNtwinSystem = 0_pInt
 integer(pInt) :: i,j,myNslip,myNtwin,myStructure = 0_pInt
 logical :: processMe

 processMe = .false.

 select case(struct(1:3))                          ! check first three chars of structure name
   case ('fcc')
     myStructure = 1_pInt
     myNslipSystem = lattice_fcc_NslipSystem       ! size of slip system families
     myNtwinSystem = lattice_fcc_NtwinSystem       ! size of twin system families
     myNslip = lattice_fcc_Nslip                   ! overall number of slip systems
     myNtwin = lattice_fcc_Ntwin                   ! overall number of twin systems
     lattice_fcc_Nstructure = lattice_fcc_Nstructure + 1_pInt    ! count fcc instances
     if (lattice_fcc_Nstructure == 1_pInt) then    ! me is first fcc structure
       processMe = .true.
       NnonSchmid(myStructure) = NnonSchmid_fcc    ! Currently no known non schmid contributions for FCC (to be changed later)
       do i = 1_pInt,myNslip                            ! assign slip system vectors
         sd(1:3,i) = lattice_fcc_systemSlip(1:3,i)
         sn(1:3,i) = lattice_fcc_systemSlip(4:6,i)
         do j = 1_pInt, NnonSchmid_fcc
           sns(1:6,j,i)  = math_Mandel33to6(lattice_nonSchmid_fcc(1:3,1:3,1,j,i))
           sns(7:12,j,i) = math_Mandel33to6(lattice_nonSchmid_fcc(1:3,1:3,2,j,i))
         enddo  
       enddo
       do i = 1_pInt,myNtwin                            ! assign twin system vectors and shears
         td(1:3,i) = lattice_fcc_systemTwin(1:3,i)
         tn(1:3,i) = lattice_fcc_systemTwin(4:6,i)
         ts(i)     = lattice_fcc_shearTwin(i)
       enddo
       interactionSlipSlip => lattice_fcc_interactionSlipSlip
       interactionSlipTwin => lattice_fcc_interactionSlipTwin
       interactionTwinSlip => lattice_fcc_interactionTwinSlip
       interactionTwinTwin => lattice_fcc_interactionTwinTwin
     endif
     
   case ('bcc')
     myStructure = 2_pInt
     myNslipSystem = lattice_bcc_NslipSystem       ! size of slip system families
     myNtwinSystem = lattice_bcc_NtwinSystem       ! size of twin system families
     myNslip = lattice_bcc_Nslip                   ! overall number of slip systems
     myNtwin = lattice_bcc_Ntwin                   ! overall number of twin systems
     lattice_bcc_Nstructure = lattice_bcc_Nstructure + 1_pInt    ! count bcc instances
     if (lattice_bcc_Nstructure == 1_pInt) then    ! me is first bcc structure
       processMe = .true.
       NnonSchmid(myStructure) = NnonSchmid_BCC    ! 5 known non schmid contributions for BCC (A. Koester, A. Ma, A. Hartmaier 2012)
       do i = 1_pInt,myNslip                            ! assign slip system vectors
         sd(1:3,i) = lattice_bcc_systemSlip(1:3,i)
         sn(1:3,i) = lattice_bcc_systemSlip(4:6,i)
         do j = 1_pInt, NnonSchmid_bcc
           sns(1:6,j,i)  = math_Mandel33to6(lattice_nonSchmid_bcc(1:3,1:3,1,j,i))
           sns(7:12,j,i) = math_Mandel33to6(lattice_nonSchmid_bcc(1:3,1:3,2,j,i))
         enddo  
       enddo
       do i = 1_pInt,myNtwin                            ! assign twin system vectors and shears
         td(1:3,i) = lattice_bcc_systemTwin(1:3,i)
         tn(1:3,i) = lattice_bcc_systemTwin(4:6,i)
         ts(i)     = lattice_bcc_shearTwin(i)
       enddo
       interactionSlipSlip => lattice_bcc_interactionSlipSlip
       interactionSlipTwin => lattice_bcc_interactionSlipTwin
       interactionTwinSlip => lattice_bcc_interactionTwinSlip
       interactionTwinTwin => lattice_bcc_interactionTwinTwin
     endif
     
   case ('hex')
     if (CoverA >= 1.0_pReal) then                 ! checking physical significance of c/a
       lattice_hex_Nstructure = lattice_hex_Nstructure + 1_pInt  ! count instances of hex structures
       myStructure = 2_pInt + lattice_hex_Nstructure             ! 3,4,5,.. for hex
       myNslipSystem = lattice_hex_NslipSystem     ! size of slip system families
       myNtwinSystem = lattice_hex_NtwinSystem     ! size of twin system families
       myNslip = lattice_hex_Nslip                 ! overall number of slip systems
       myNtwin = lattice_hex_Ntwin                 ! overall number of twin systems
       processMe = .true.
       NnonSchmid(myStructure) = NnonSchmid_hex    ! Currently no known non schmid contributions for hex (to be changed later)
! converting from 4 axes coordinate system (a1=a2=a3=c) to ortho-hexgonal system (a, b, c)
       do i = 1_pInt,myNslip
         sd(1,i) =  lattice_hex_systemSlip(1,i)*1.5_pReal ! direction [uvtw]->[3u/2 (u+2v)*sqrt(3)/2 w*(c/a)]
         sd(2,i) = (lattice_hex_systemSlip(1,i)+2.0_pReal*lattice_hex_systemSlip(2,i))*(0.5_pReal*sqrt(3.0_pReal))
         sd(3,i) =  lattice_hex_systemSlip(4,i)*CoverA
         sn(1,i) =  lattice_hex_systemSlip(5,i)           ! plane (hkil)->(h (h+2k)/sqrt(3) l/(c/a))
         sn(2,i) = (lattice_hex_systemSlip(5,i)+2.0_pReal*lattice_hex_systemSlip(6,i))/sqrt(3.0_pReal)
         sn(3,i) =  lattice_hex_systemSlip(8,i)/CoverA
         do j = 1_pInt, NnonSchmid_hex
           sns(1:6,j,i)  = math_Mandel33to6(lattice_nonSchmid_hex(1:3,1:3,1,j,i))
           sns(7:12,j,i) = math_Mandel33to6(lattice_nonSchmid_hex(1:3,1:3,2,j,i))
         enddo  
       enddo
       do i = 1_pInt,myNtwin
         td(1,i) =  lattice_hex_systemTwin(1,i)*1.5_pReal
         td(2,i) = (lattice_hex_systemTwin(1,i)+2.0_pReal*lattice_hex_systemTwin(2,i))*(0.5_pReal*sqrt(3.0_pReal))
         td(3,i) =  lattice_hex_systemTwin(4,i)*CoverA
         tn(1,i) =  lattice_hex_systemTwin(5,i)
         tn(2,i) = (lattice_hex_systemTwin(5,i)+2.0_pReal*lattice_hex_systemTwin(6,i))/sqrt(3.0_pReal)
         tn(3,i) =  lattice_hex_systemTwin(8,i)/CoverA

         select case(lattice_hex_shearTwin(i))                                          ! from Christian & Mahajan 1995 p.29
           case (1_pInt)                                                                ! <-10.1>{10.2}
                    ts(i) = (3.0_pReal-CoverA*CoverA)/sqrt(3.0_pReal)/CoverA
           case (2_pInt)                                                                ! <11.6>{-1-1.1}
                    ts(i) = 1.0_pReal/CoverA
           case (3_pInt)                                                                ! <10.-2>{10.1}
                    ts(i) = (4.0_pReal*CoverA*CoverA-9.0_pReal)/4.0_pReal/sqrt(3.0_pReal)/CoverA
           case (4_pInt)                                                                ! <11.-3>{11.2}
                    ts(i) = 2.0_pReal*(CoverA*CoverA-2.0_pReal)/3.0_pReal/CoverA
         end select

       enddo
       interactionSlipSlip => lattice_hex_interactionSlipSlip
       interactionSlipTwin => lattice_hex_interactionSlipTwin
       interactionTwinSlip => lattice_hex_interactionTwinSlip
       interactionTwinTwin => lattice_hex_interactionTwinTwin
     endif
 end select

 if (processMe) then
   if  (myStructure > lattice_Nstructure) &
     call IO_error(666_pInt,myStructure,ext_msg = 'structure index out of bounds')                  ! check for memory leakage
   do i = 1_pInt,myNslip                                                                            ! store slip system vectors and Schmid matrix for my structure
     lattice_sd(1:3,i,myStructure) = sd(1:3,i)/math_norm3(sd(1:3,i))                                ! make unit vector
     lattice_sn(1:3,i,myStructure) = sn(1:3,i)/math_norm3(sn(1:3,i))                                ! make unit vector
     lattice_st(1:3,i,myStructure) = math_vectorproduct(lattice_sd(1:3,i,myStructure), &
                                                        lattice_sn(1:3,i,myStructure))
     lattice_Sslip(1:3,1:3,i,myStructure) = math_tensorproduct(lattice_sd(1:3,i,myStructure), &
                                                               lattice_sn(1:3,i,myStructure))
     lattice_Sslip_v(1:6,1,i,myStructure) = math_Mandel33to6(math_symmetric33(lattice_Sslip(1:3,1:3,i,myStructure)))
     do j = 1_pInt, NnonSchmid(myStructure)
       lattice_Sslip_v(1:6,2*j,i,myStructure)   = sns(1:6,j,i)
       lattice_Sslip_v(1:6,2*j+1,i,myStructure) = sns(7:12,j,i)
     enddo 
     if (abs(math_trace33(lattice_Sslip(1:3,1:3,i,myStructure))) > 1.0e-8_pReal) &
       call IO_error(0_pInt,myStructure,i,0_pInt,ext_msg = 'dilatational slip Schmid matrix')
   enddo
   do i = 1_pInt,myNtwin                                                                            ! store twin system vectors and Schmid plus rotation matrix for my structure
     lattice_td(1:3,i,myStructure) = td(1:3,i)/math_norm3(td(1:3,i))                                ! make unit vector
     lattice_tn(1:3,i,myStructure) = tn(1:3,i)/math_norm3(tn(1:3,i))                                ! make unit vector
     lattice_tt(1:3,i,myStructure) = math_vectorproduct(lattice_td(1:3,i,myStructure), &
                                                        lattice_tn(1:3,i,myStructure))
     lattice_Stwin(1:3,1:3,i,myStructure) = math_tensorproduct(lattice_td(1:3,i,myStructure), &
                                                               lattice_tn(1:3,i,myStructure))
     lattice_Stwin_v(1:6,i,myStructure)   = math_Mandel33to6(math_symmetric33(lattice_Stwin(1:3,1:3,i,myStructure)))
     lattice_Qtwin(1:3,1:3,i,myStructure) = math_axisAngleToR(tn(1:3,i),180.0_pReal*INRAD)
     lattice_shearTwin(i,myStructure)     = ts(i)
     if (abs(math_trace33(lattice_Stwin(1:3,1:3,i,myStructure))) > 1.0e-8_pReal) &
       call IO_error(0_pInt,myStructure,i,0_pInt,ext_msg = 'dilatational twin Schmid matrix')
   enddo
   lattice_NslipSystem(1:lattice_maxNslipFamily,myStructure) = myNslipSystem                        ! number of slip systems in each family
   lattice_NtwinSystem(1:lattice_maxNtwinFamily,myStructure) = myNtwinSystem                        ! number of twin systems in each family
   lattice_interactionSlipSlip(1:myNslip,1:myNslip,myStructure) = interactionSlipSlip(1:myNslip,1:myNslip)
   lattice_interactionSlipTwin(1:myNslip,1:myNtwin,myStructure) = interactionSlipTwin(1:myNslip,1:myNtwin)
   lattice_interactionTwinSlip(1:myNtwin,1:myNslip,myStructure) = interactionTwinSlip(1:myNtwin,1:myNslip)
   lattice_interactionTwinTwin(1:myNtwin,1:myNtwin,myStructure) = interactionTwinTwin(1:myNtwin,1:myNtwin)
 endif

 lattice_initializeStructure = myStructure                                                          ! report my structure index back

end function lattice_initializeStructure


!--------------------------------------------------------------------------------------------------
!> @brief Maps structure to symmetry type 
!> @details fcc(1) and bcc(2) are cubic(1) hex(3+) is hexagonal(2)
!--------------------------------------------------------------------------------------------------
integer(pInt) pure function lattice_symmetryType(structName)

 implicit none
 character(len=32), intent(in) :: structName

 select case(structName(1:3))
   case ('fcc','bcc')
     lattice_symmetryType = 1_pInt
   case ('hex')
     lattice_symmetryType = 2_pInt
   case default
     lattice_symmetryType = 0_pInt
  end select

 return
 
end function lattice_symmetryType


!--------------------------------------------------------------------------------------------------
!> @brief Symmetrizes stiffness matrix according to lattice type
!--------------------------------------------------------------------------------------------------
pure function lattice_symmetrizeC66(structName,C66)

 implicit none
 character(len=32), intent(in) :: structName
 real(pReal), dimension(6,6), intent(in) :: C66
 real(pReal), dimension(6,6) :: lattice_symmetrizeC66
 integer(pInt) :: j,k

 lattice_symmetrizeC66 = 0.0_pReal
 
 select case(structName(1:3))
   case ('iso')
     forall(k=1_pInt:3_pInt)
       forall(j=1_pInt:3_pInt) lattice_symmetrizeC66(k,j) = C66(1,2)
       lattice_symmetrizeC66(k,k) = C66(1,1)
       lattice_symmetrizeC66(k+3,k+3) = 0.5_pReal*(C66(1,1)-C66(1,2))
     end forall
   case ('fcc','bcc')
     forall(k=1_pInt:3_pInt)
       forall(j=1_pInt:3_pInt) lattice_symmetrizeC66(k,j) =   C66(1,2)
       lattice_symmetrizeC66(k,k) =     C66(1,1)
       lattice_symmetrizeC66(k+3_pInt,k+3_pInt) = C66(4,4)
     end forall    
   case ('hex')
     lattice_symmetrizeC66(1,1) = C66(1,1)
     lattice_symmetrizeC66(2,2) = C66(1,1)
     lattice_symmetrizeC66(3,3) = C66(3,3)
     lattice_symmetrizeC66(1,2) = C66(1,2)
     lattice_symmetrizeC66(2,1) = C66(1,2)
     lattice_symmetrizeC66(1,3) = C66(1,3)
     lattice_symmetrizeC66(3,1) = C66(1,3)
     lattice_symmetrizeC66(2,3) = C66(1,3)
     lattice_symmetrizeC66(3,2) = C66(1,3)
     lattice_symmetrizeC66(4,4) = C66(4,4)
     lattice_symmetrizeC66(5,5) = C66(4,4)
     lattice_symmetrizeC66(6,6) = 0.5_pReal*(C66(1,1)-C66(1,2))
   case ('ort')
     lattice_symmetrizeC66(1,1) = C66(1,1)
     lattice_symmetrizeC66(2,2) = C66(2,2)
     lattice_symmetrizeC66(3,3) = C66(3,3)
     lattice_symmetrizeC66(1,2) = C66(1,2)
     lattice_symmetrizeC66(2,1) = C66(1,2)
     lattice_symmetrizeC66(1,3) = C66(1,3)
     lattice_symmetrizeC66(3,1) = C66(1,3)
     lattice_symmetrizeC66(2,3) = C66(2,3)
     lattice_symmetrizeC66(3,2) = C66(2,3)
     lattice_symmetrizeC66(4,4) = C66(4,4)
     lattice_symmetrizeC66(5,5) = C66(5,5)
     lattice_symmetrizeC66(6,6) = C66(6,6)
  end select
  
 end function lattice_symmetrizeC66


!--------------------------------------------------------------------------------------------------
!> @brief   Number of parameters to expect in material.config section
! NslipFamilies
! NtwinFamilies
! SlipSlipInteraction
! SlipTwinInteraction
! TwinSlipInteraction
! TwinTwinInteraction
!--------------------------------------------------------------------------------------------------
function lattice_configNchunks(struct)
 use prec, only: &
   pInt

 implicit none
 integer(pInt), dimension(6)  :: lattice_configNchunks
 character(len=*), intent(in) :: struct

 select case(struct(1:3))                                                                           ! check first three chars of structure name
   case ('fcc')
     lattice_configNchunks(1) = count(lattice_fcc_NslipSystem > 0_pInt)
     lattice_configNchunks(2) = count(lattice_fcc_NtwinSystem > 0_pInt)
     lattice_configNchunks(3) = maxval(lattice_fcc_interactionSlipSlip)
     lattice_configNchunks(4) = maxval(lattice_fcc_interactionSlipTwin)
     lattice_configNchunks(5) = maxval(lattice_fcc_interactionTwinSlip)
     lattice_configNchunks(6) = maxval(lattice_fcc_interactionTwinTwin)
   case ('bcc')
     lattice_configNchunks(1) = count(lattice_bcc_NslipSystem > 0_pInt)
     lattice_configNchunks(2) = count(lattice_bcc_NtwinSystem > 0_pInt)
     lattice_configNchunks(3) = maxval(lattice_bcc_interactionSlipSlip)
     lattice_configNchunks(4) = maxval(lattice_bcc_interactionSlipTwin)
     lattice_configNchunks(5) = maxval(lattice_bcc_interactionTwinSlip)
     lattice_configNchunks(6) = maxval(lattice_bcc_interactionTwinTwin)
   case ('hex')
     lattice_configNchunks(1) = count(lattice_hex_NslipSystem > 0_pInt)
     lattice_configNchunks(2) = count(lattice_hex_NtwinSystem > 0_pInt)
     lattice_configNchunks(3) = maxval(lattice_hex_interactionSlipSlip)
     lattice_configNchunks(4) = maxval(lattice_hex_interactionSlipTwin)
     lattice_configNchunks(5) = maxval(lattice_hex_interactionTwinSlip)
     lattice_configNchunks(6) = maxval(lattice_hex_interactionTwinTwin)
 end select

end function lattice_configNchunks

end module lattice