Minor changes to decrease validation time in top compatibility during…

… checking

gmso/utils/compatibility.py

@@ -29,7 +29,7 @@ def check_compatibility(topology, accepted_potentials):
     """
     potential_forms_dict = dict()
     for atom_type in topology.atom_types(
-        filter_by=PotentialFilters.UNIQUE_NAME_CLASS
+        filter_by=PotentialFilters.UNIQUE_EXPRESSION
     ):
         potential_form = _check_single_potential(
             atom_type,
@@ -43,7 +43,7 @@ def check_compatibility(topology, accepted_potentials):
             potential_forms_dict.update(potential_form)
 
     for connection_type in topology.connection_types(
-        # filter_by=PotentialFilters.UNIQUE_NAME_CLASS
+        filter_by=PotentialFilters.UNIQUE_EXPRESSION
     ):
         potential_form = _check_single_potential(
             connection_type,

gmso/utils/conversions.py

@@ -3,6 +3,7 @@
 from functools import lru_cache
 
 import numpy as np
+import symengine
 import sympy
 import unyt as u
 from unyt.dimensions import length, mass, time
@@ -20,7 +21,8 @@ def _constant_multiplier(pot1, pot2):
     # TODO: Test outputs
     # TODO: Check speed
     try:
-        constant = sympy.simplify(pot1.expression / pot2.expression)
+        constant = symengine.expand(pot1.expression / pot2.expression)
+        # constant = sympy.simplify(pot1.expression / pot2.expression)
         if constant.is_number:
             for eq_term in pot1.expression.args:
                 if eq_term.is_symbol:
@@ -35,6 +37,7 @@ def _constant_multiplier(pot1, pot2):
 sympy_conversionsList = [_constant_multiplier]
 
 
+@lru_cache(maxsize=128)
 def _try_sympy_conversions(pot1, pot2):
     # TODO: Doc string
     # TODO: Test outputs