diff --git a/code/lattice.f90 b/code/lattice.f90
index 80e6dcb72..920a2eefd 100644
--- a/code/lattice.f90
+++ b/code/lattice.f90
@@ -261,32 +261,32 @@ module lattice
       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  &
+      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 :: &
@@ -383,7 +383,7 @@ module lattice
      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 &
+     3,2,3,3,3,3,2,3,3,3,3,1  &
      ],pInt),[lattice_bcc_Nslip,lattice_bcc_Ntwin],order=[2,1])
     !< Interaction types
     !< 1 --- coplanar interaction
@@ -396,9 +396,24 @@ module lattice
 
 !> twin-twin interactions for BCC structures (2) MISSING: not implemented yet
  integer(pInt), dimension(lattice_bcc_Ntwin,lattice_bcc_Ntwin), target, private :: &
-   lattice_bcc_interactionTwinTwin = 0_pInt
- 
-
+   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])
+    !< Interaction types
+    !< 1 --- self interaction
+    !< 2 --- coplinear interaction
+    !< 3 --- hardened interaction
 !--------------------------------------------------------------------------------------------------
 ! hex (3+)