I/O inter-version compatibility

Hi all,

I have a general question about using one version of gromacs that takes as input earlier outputs produced with an earlier version.

Example: PMF calculations and a persistent observation I have made. I produce a series of gro file configs at the pulling stage using one Gromacs version. I then attempt the series of zero-velocity pulls of these configs for the WHAM calculation. If the Gromacs version for the latter is different from that used to generate the configs, mdrun crashes with some infinite energy complaint. The difference between versions won’t even be very big: today I observed this with versions that are ~4 months apart. When the versions are identical, the issue disappears.
I thought .gro files were more or less universally usable in Gromacs, as they contain position and velocity data with reasonable accuracy.

Granted, it is not necessarily a big deal, but what is happening? Thanks!

Which GROMACS version do you work with? and when you speak about different versions I guess you refer to different minor releases (same year but different year)

Hi Alessandra,

This occurs between 2018 and 2022 (unfortunately, I do not remember minor versions). On top of that, 2022 gmx wham exits when the umbrella pull data is from an earlier 2022 version (3-4 months apart).