CGenFF problem (versions are not equivalent!)

User discussions
1

GROMACS version: 2020
GROMACS modification: No

Hello,
I have downloaded the latest charmm36-feb2021.ff port which is having Cgenff version 4.4 in forcefield .doc file . but the .str file generated from the CGENFF program is having cgenff version 4.5. hence showing error.

WARNING: CGenFF versions are not equivalent!

I used also charmm36-Jul2021.ff
I got the same error

WARNING: CGenFF versions are not equivalent!

The CGenFF version in .str file (4.5)
The CGenFF version in charmm36-JFeb2021.ff (4.4)
The CGenFF version in charmm36-Jul2021.ff (4.6)

I used this server https://cgenff.umaryland.edu/initguess/ to generate srt files
how to resolve this issue. kindly help

2

See if grompp complains about duplicate parameters. If it does, delete the offending lines from the .prm file and use those found in the parent force field. If there’s no conflict, then you can proceed without any problem. Sometimes the CGenFF server lags behind the official force field release; you can contact Alex MacKerell to see if his group can fix that.