[gmx-users] density problems when switching from md to sd integrator
anaome at fundp.ac.be
Thu Jan 28 10:38:41 CET 2010
I'm simulating a box of cyclohexane (GROMOS 53a6, 512 molecules, 298K,
compressibility=11.2 10-5 bar-,1 tau_p=0.5 ps, no constraints on bonds).
After equilibration and NPT simulation, the system reaches the proper
density reported for the model (791g/L). When I switch to a stochastic
integrator (with inverse friction coeff. tau_t=0.2 ps) the density
rapidly falls to about 765g/L, the potential energy increases, while
temperature and pressure fluctuate much more around their specified
values. I intend to use this box of cyclohexane for solvation free
energy calculations. Can anyone explain what is going on?
Thanks in advance
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 318 bytes
Desc: not available
More information about the gromacs.org_gmx-users