diff --git a/trunk/constitutive_j2.f90 b/trunk/constitutive_j2.f90
index c17ce019e..7359f095d 100644
--- a/trunk/constitutive_j2.f90
+++ b/trunk/constitutive_j2.f90
@@ -11,7 +11,7 @@
 !	constitution            j2
 !	(output)                flowstress
 !	(output)                strainrate
-!	c11                     110.9e9    # (3 C11 + 2 C12 + 2 C44) / 5
+!	c11                     110.9e9    # (3 C11 + 2 C12 + 2 C44) / 5  ... with C44 = C11-C12 !!
 !	c12                     58.34e9    # (1 C11 + 4 C12 - 1 C44) / 5
 !	taylorfactor            3
 !	s0                      31e6
@@ -281,30 +281,33 @@ subroutine constitutive_j2_LpAndItsTangent(Lp,dLp_dTstar,Tstar_v,Temperature,sta
  real(pReal), dimension(3,3) :: Lp
  real(pReal), dimension(3,3,3,3) :: dLp_dTstar3333
  real(pReal), dimension(9,9) :: dLp_dTstar
- real(pReal) norm_Tstar
- real(pReal) factor
+ real(pReal) norm_Tstar, squarenorm_Tstar, factor
+ 
  matID = phase_constitutionInstance(material_phase(ipc,ip,el))
 
  Tstar33 = math_Mandel6to33(Tstar_v)
- norm_Tstar = dsqrt(math_mul6x6(Tstar_v,Tstar_v))
-  
+ squarenorm_Tstar = math_mul6x6(Tstar_v,Tstar_v)
+ norm_Tstar = dsqrt(Tstar) 
+
 !* Calculation of Lp
  Lp = Tstar33/norm_Tstar*constitutive_j2_gdot0(matID)/constitutive_j2_fTaylor(matID)* &
       (dsqrt(1.5_pReal)/constitutive_j2_fTaylor(matID)*norm_Tstar/state(ipc,ip,el)%p(1))**constitutive_j2_n(matID)
 
 !* Calculation of the tangent of Lp
+ factor = constitutive_j2_gdot0(matID)/constitutive_j2_fTaylor(matID)* &
+          (dsqrt(1.5_pReal)/ constitutive_j2_fTaylor(matID)/state(ipc,ip,el)%p(1))**constitutive_j2_n(matID) * &
+          norm_Tstar**(constitutive_j2_n(matID)-1.0_pReal)
+
  dLp_dTstar3333 = 0.0_pReal
  dLp_dTstar = 0.0_pReal
- factor = constitutive_j2_gdot0(matID)/constitutive_j2_fTaylor(matID)* &
-	  (dsqrt(1.5_pReal)/ constitutive_j2_fTaylor(matID)/state(ipc,ip,el)%p(1))**constitutive_j2_n(matID) * &
-		  * norm_Tstar**(constitutive_j2_n(matID)-1.0_pReal)
  forall (k=1:3,l=1:3,m=1:3,n=1:3) &
-      dLp_dTstar3333(k,l,m,n) = factor * (constitutive_j2_n(matID)-1.0_pReal)/(norm_Tstar**2.0_pReal) * Tstar33(k,l)*Tstar33(m,n)
+   dLp_dTstar3333(k,l,m,n) = Tstar33(k,l)*Tstar33(m,n) * (constitutive_j2_n(matID)-1.0_pReal)/squarenorm_Tstar
  forall (k=1:3,l=1:3) &
-	  dLp_dTstar3333(k,l,k,l) = dLp_dTstar3333(k,l,k,l) + factor
- dLp_dTstar = math_Plain3333to99(dLp_dTstar3333)
+   dLp_dTstar3333(k,k,l,l) = dLp_dTstar3333(k,k,l,l) + 1.0_pReal
+ dLp_dTstar = math_Plain3333to99(factor * dLp_dTstar3333)
 
  return
+
 end subroutine
 
 
@@ -340,9 +343,9 @@ function constitutive_j2_dotState(Tstar_v,Temperature,state,ipc,ip,el)
  norm_Tstar = dsqrt(math_mul6x6(Tstar_v,Tstar_v))
  constitutive_j2_dotState = constitutive_j2_gdot0(matID)/constitutive_j2_fTaylor(matID)* &
                             (dsqrt(1.5_pReal)/constitutive_j2_fTaylor(matID)*norm_Tstar/state(ipc,ip,el)%p(1))** &
-							constitutive_j2_n(matID) * &
-							constitutive_j2_h0(matID)*(1.0_pReal-state(ipc,ip,el)%p(1)/constitutive_j2_s_sat(matID))** &
-							constitutive_j2_w0(matID)
+                            constitutive_j2_n(matID) * &
+                            constitutive_j2_h0(matID)*(1.0_pReal-state(ipc,ip,el)%p(1)/constitutive_j2_s_sat(matID))** &
+                            constitutive_j2_w0(matID)
 
  return
 
@@ -387,9 +390,9 @@ pure function constitutive_j2_postResults(Tstar_v,Temperature,dt,state,ipc,ip,el
        constitutive_j2_postResults(c+1) = state(ipc,ip,el)%p(1)
        c = c + 1
      case ('strainrate')
-	   constitutive_j2_postResults(c+1) = constitutive_j2_gdot0(matID)/constitutive_j2_fTaylor(matID)* &
+       constitutive_j2_postResults(c+1) = constitutive_j2_gdot0(matID)/constitutive_j2_fTaylor(matID)* &
                                           (dsqrt(1.5_pReal)/constitutive_j2_fTaylor(matID)*norm_Tstar/state(ipc,ip,el)%p(1))** &
-										  constitutive_j2_n(matID)
+                                          constitutive_j2_n(matID)
        c = c + 1
    end select
  enddo