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Hi all,<br>
<br>
I'm working on MD simluations including Free energy calculations of
polarizable water and polarizable ions. Normal MD simulations for
water and ions are working fine. But when starting Free Energy
calculation for ions+water, the simulation immediately aborts,
giving the error:<br>
<br>
<i>Program mdrun_d, VERSION 4.5.5<br>
Source code file: [...]/src/gromacs-4.5.5/src/mdlib/shellfc.c,
line: 365<br>
<br>
Fatal error:<br>
polarize can not be used with qA != qB</i><br>
<br>
Indeed, the ion force field consists only of the atom and the shell
particle with different charges:<br>
<br>
[ atoms ]<br>
; id at type res nr residu name at name cg nr charge<br>
1 ClA 1 ClI ClA 1
2.630841e+00<br>
2 ClS 1 ClI ClS 1
-3.630841e+00<br>
<br>
Even in the case, when init-lambda=0, which should be equal to a
normal MD run, the error is obtained.<br>
<br>
The lines to control Free Energy calculations are the following:<br>
<br>
<i>free-energy = yes<br>
init-lambda = 0.0<br>
delta-lambda = 0.00<br>
foreign_lambda = 0.167<br>
sc-alpha = 0.0 ; soft core is turned off for Coulomb
decoupling<br>
sc-sigma = 0.0<br>
sc_power = 1.0<br>
<br>
couple-moltype = solute ; name of moleculetype to
decouple<br>
couple-lambda0 = vdw-q ; all interactions are on at
start<br>
couple-lambda1 = vdw ; turn off coulomb interaction<br>
couple-intramol = no<br>
nstdhdl = 100<br>
<br>
separate_dhdl_file = yes</i><br>
<br>
Free Energy calculation works for non-polarizable ff. If someone
could help me, I would be very grateful.<br>
<br>
Best<br>
Tom<br>
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