diff --git a/src/math.f90 b/src/math.f90
index a6a3498e0..ac0974995 100644
--- a/src/math.f90
+++ b/src/math.f90
@@ -1022,70 +1022,6 @@ pure function math_eigenvectorBasisSym33(m)
 end function math_eigenvectorBasisSym33
 
 
-!--------------------------------------------------------------------------------------------------
-!> @brief logarithm eigenvector basis of symmetric 33 matrix m
-!--------------------------------------------------------------------------------------------------
-pure function math_eigenvectorBasisSym33_log(m)
-
-  real(pReal), dimension(3,3)              :: math_eigenvectorBasisSym33_log
-  real(pReal), dimension(3)                :: invariants, values
-  real(pReal), dimension(3,3), intent(in) :: m
-  real(pReal) :: P, Q, rho, phi
-  real(pReal), parameter :: TOL=1.e-14_pReal
-  real(pReal), dimension(3,3,3) :: N, EB
-
-  invariants = math_invariantsSym33(m)
-  EB = 0.0_pReal
-
-  P = invariants(2)-invariants(1)**2.0_pReal/3.0_pReal
-  Q = -2.0_pReal/27.0_pReal*invariants(1)**3.0_pReal+product(invariants(1:2))/3.0_pReal-invariants(3)
-
-  threeSimilarEigenvalues: if(all(abs([P,Q]) < TOL)) then
-    values = invariants(1)/3.0_pReal
-  ! this is not really correct, but at least the basis is correct
-    EB(1,1,1)=1.0_pReal
-    EB(2,2,2)=1.0_pReal
-    EB(3,3,3)=1.0_pReal
-  else threeSimilarEigenvalues
-    rho=sqrt(-3.0_pReal*P**3.0_pReal)/9.0_pReal
-    phi=acos(math_clip(-Q/rho*0.5_pReal,-1.0_pReal,1.0_pReal))
-    values = 2.0_pReal*rho**(1.0_pReal/3.0_pReal)* &
-                              [cos(phi/3.0_pReal), &
-                               cos((phi+2.0_pReal*PI)/3.0_pReal), &
-                               cos((phi+4.0_pReal*PI)/3.0_pReal) &
-                              ] + invariants(1)/3.0_pReal
-    N(1:3,1:3,1) = m-values(1)*math_I3
-    N(1:3,1:3,2) = m-values(2)*math_I3
-    N(1:3,1:3,3) = m-values(3)*math_I3
-    twoSimilarEigenvalues: if(abs(values(1)-values(2)) < TOL) then
-      EB(1:3,1:3,3)=matmul(N(1:3,1:3,1),N(1:3,1:3,2))/ &
-                                                ((values(3)-values(1))*(values(3)-values(2)))
-      EB(1:3,1:3,1)=math_I3-EB(1:3,1:3,3)
-    elseif(abs(values(2)-values(3)) < TOL) then twoSimilarEigenvalues
-      EB(1:3,1:3,1)=matmul(N(1:3,1:3,2),N(1:3,1:3,3))/ &
-                                                ((values(1)-values(2))*(values(1)-values(3)))
-      EB(1:3,1:3,2)=math_I3-EB(1:3,1:3,1)
-    elseif(abs(values(3)-values(1)) < TOL) then twoSimilarEigenvalues
-      EB(1:3,1:3,2)=matmul(N(1:3,1:3,1),N(1:3,1:3,3))/ &
-                                                ((values(2)-values(1))*(values(2)-values(3)))
-      EB(1:3,1:3,1)=math_I3-EB(1:3,1:3,2)
-    else twoSimilarEigenvalues
-      EB(1:3,1:3,1)=matmul(N(1:3,1:3,2),N(1:3,1:3,3))/ &
-                                                ((values(1)-values(2))*(values(1)-values(3)))
-      EB(1:3,1:3,2)=matmul(N(1:3,1:3,1),N(1:3,1:3,3))/ &
-                                                ((values(2)-values(1))*(values(2)-values(3)))
-      EB(1:3,1:3,3)=matmul(N(1:3,1:3,1),N(1:3,1:3,2))/ &
-                                                ((values(3)-values(1))*(values(3)-values(2)))
-    endif twoSimilarEigenvalues
-  endif threeSimilarEigenvalues
-
-  math_eigenvectorBasisSym33_log = log(sqrt(values(1))) * EB(1:3,1:3,1) &
-                                 + log(sqrt(values(2))) * EB(1:3,1:3,2) &
-                                 + log(sqrt(values(3))) * EB(1:3,1:3,3)
-
-end function math_eigenvectorBasisSym33_log
-
-
 !--------------------------------------------------------------------------------------------------
 !> @brief rotational part from polar decomposition of 33 tensor m
 !--------------------------------------------------------------------------------------------------