Hi all,<br><br>I am not a CS person, but I did find something in acpype.py as <br><br>.............<br> if phase in [0, 180]:<br> properDihedralsGmx45.append([item[0].atoms, phaseRaw, kPhi, period])<br>
if not self.gmx45:<br> if kPhi > 0: V[period] = 2 * kPhi * cal<br> if period == 1:<br> C[0] += 0.5 * V[period]<br> if phase == 0:<br>
C[1] -= 0.5 * V[period]<br> else:<br> C[1] += 0.5 * V[period]<br> elif period == 2:<br>......................<br>
<br>kPhi here seems to be the dihedral force constant, and it seems if kPhi < 0, no value will be assigned to C[0], C[1], C[2] ...<br><br>I wonder if the negative dihedral force constants problem could be solved by changing 'kPhi > 0' to 'kPhi != 0' for acpype?<br>
<br>Thanks,<br><br>Yun<br>