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High dplumed values and zero exchange probability

Open LubaSim opened this issue 1 year ago • 1 comments

Dear Plumed Users,

I'm running FEP/HREX simulation using Gromacs-2021.7 patched with plumed-2.8.3. However, I get zero probability exchange between the replicas and also high dplumed values, although the difference between the potential energy values in two adjacent replicas is not high. I would like to calculate manually the dplumed energy in order to check that. According to the code /data/plumed-2.8.3/patches/gromacs-2021.7.diff/src/gromacs/mdrun/replicaexchange.cpp, dplumed is calculated as: dplumed=adb * re->beta[a]+bdb * re->beta[b]

Could you please help me to understand how the values "adb" and "bdb" are calculated or where I can find them (I guess these are potential energies).

Thanks in advance, Luba

LubaSim avatar Dec 10 '24 09:12 LubaSim

Replica exchange at step 99800 time 199.60001 Repl 1 <-> 2 dE_term = -0.000e+00 (kT) dpV = 0.000e+00 d = 0.000e+00 Repl 1: adb = 1.532e+03 beta[a] = 3.880e-01; Repl 2: bdb = -1.082e+03 beta[b] = 3.880e-01 dplumed = 1.743e+02 dE_Term = 1.743e+02 (kT) Repl ex 0 1 2 3 4 5 x 6 7 8 9 10 11 Repl pr .00 .00 1.0 .03 .21 me too.

wu222222 avatar Jan 11 '25 06:01 wu222222