Conversion from c6 and c12 = 0 to sigma epsilon

From: Sourav Ray (
Date: Sat May 14 2016 - 06:29:49 CDT


For two particles without LJ interaction, the c6 and c12 values (in GROMACS
topology file) are set to 0. If I would like to incorporate the same to a
CHARMM parameter file, I need to convert them to sigma-epsilon form.

Since the usual conversion formula will result in 'divide by 0' error. I
presume we can set epsilon = 0 and sigma to some arbitrarily high value
well beyond the LJ cut off (or any random value because epsilon is zero),
any suggestions?

Thanks and regards

This archive was generated by hypermail 2.1.6 : Tue Dec 27 2016 - 23:22:07 CST