BUGFIX: sign for LHS bulkDMIimplicit(TPS2)

integrators/_forms/blf_piImplicit.py

@@ -11,7 +11,7 @@ class BilinearForms_piImplicit:
 
 
   def _DerivLinearTerms_pi_Implicit_LHS(self):
-    return self._theta * self._k \
+    return -self._theta * self._k \
       * self._DerivDzyaloshinskiiMoriya_Implicit_LHS_Term()