[gmx-users] remd ... is it exchanging?

[Carsten Baldauf]

dear all//
i am trying to run remd simulations on a 16 residue peptide using 16 
replicas in a temperature range from 275 to 419 kelvin.
i follow the method described here: Seibert, M., Patriksson, A., Hess, 
B., van der Spoel, D. Reproducible polypeptide folding and structure 
prediction using molecular dynamics simulations. J. Mol. Biol. 
354:173–183, 2005.

when i look in the *log files is think i find the sections logging the 
exchanges:
Replica exchange at step 1000 time 2
Repl 0 <-> 1 dE = 3.180e+01 dpV = 5.043e-04 d = 3.180e+01
Repl ex 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Repl pr .00 .00 .00 .00 .00 .00 .00 .00

the line 'Repl pr ' allways only contains .00's. thus i guess there is 
no exchange happening. am i right? what are the possible reasons and 
what you suggest me to change?
thanks a lot//
carsten




-- 
dr carsten baldauf
biotechnologisches zentrum der tu dresden
http://www.biotec.tu-dresden.de/pisabarro
http://www.biotec.tu-dresden.de/~carstenb

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