Fix for non-equal force constants in stretch-bend (#3420)

3516752a · Gareth-elliott · GitHub · f2cdf70a · 3516752a
Unverified Commit 3516752a authored Jan 22, 2022 by Gareth-elliott Committed by GitHub Jan 21, 2022
Show whitespace changes
Inline Side-by-side

Showing with 6 additions and 1 deletion

wrappers/python/openmm/app/forcefield.py wrappers/python/openmm/app/forcefield.py +6 -1

No files found.
--- a/wrappers/python/openmm/app/forcefield.py
+++ b/wrappers/python/openmm/app/forcefield.py
@@ -4653,7 +4653,12 @@ class AmoebaStretchBendGenerator(object):
                       raise ValueError(outputString)

                    else:
-                        force.addBond((angle[0], angle[1], angle[2]), (bondAB, bondCB, angleDict['idealAngle']/radian, self.k1[i], self.k2[i]))
+                        if type1 in types1 and type3 in types3:
+                            k1, k2 = self.k1[i], self.k2[i]
+                        else:
+                            k1, k2 = self.k2[i], self.k1[i]
+                            
+                        force.addBond((angle[0], angle[1], angle[2]), (bondAB, bondCB, angleDict['idealAngle']/radian, k1, k2))

                    break