[gmx-users] BAR / g_bar problems

[David van der Spoel]

Hi,

we have terrible problems to get reasonable results from BAR free energy 
calculations. We basically follow Justin's tutorial for solvation of 
methanol, ethanol, diethyl-ether and neopentane in water using OPLS but 
get very strange results. The free energy curves are here:

http://folding.bmc.uu.se/images/koko.jpg

Molecule  Energy Exper
Methanol     -8    -21
Ethanol      -9    -21
Diethylether -11    -7
Neopentane   -10   +11

any clue?
-- 
David van der Spoel, Ph.D., Professor of Biology
Dept. of Cell & Molec. Biol., Uppsala University.
Box 596, 75124 Uppsala, Sweden. Phone:	+46184714205.
spoel at xray.bmc.uu.se    http://folding.bmc.uu.se