Epsilon parameter unit in the LJ force field file oplsaa

User discussions
1

GROMACS version:
GROMACS modification: No
What is the epsilon parameter unit in the LJ force-field file oplsaa (ffnonbonded.itp). In the main paper, its unit is KCal/mol but the Gromacs standard unit is KJ/mol. Was this unit changed in the force field file or is it internally changed by the Gromacs during the run?

2

The parameters in the GROMACS files use kJ/mol. The parameters are converted from the original force field specification. You can verify this by doing the unit conversion yourself.

3

Thank you for your comment.