[gmx-users] Testing gromacs: Thermodynamics integration using tabulated potential
fahimeh.baftizadeh at googlemail.com
Tue May 27 15:33:00 CEST 2014
I am computing solvation free energy of molecule A in solvent B. I used two
different procedure and I thought that the results should be comparable,
however they are very different.
Thermodynamics integration using 20 lambda points. VDWtype was switch and I
used PME coulombtype. I turned off VDW and coulomb interactions both at
the same time. The free energy of solvation was 74kj/mol
Thermodynamics integration using 20 lambda points. I introduce tabulated
potential for the interaction between molecule A and molecule B. therefore
the vdwtype and columbtype was set to User. I provided two files, called
table.xvg and table_A_B.xvg which are identical for now as a test. These
files contain, r, 1/r, 1/r**2, -1/r**6, -6/r**7, 1/r**12, 12/r**13. The
other parameters for VDW interactions are untouched. The result of this
simulation however is very different ~ 50kj/mol ...
I am expecting to receive not identical but something comparable ... could
you please help me to understand this?
Many thanks in advance
More information about the gromacs.org_gmx-users