VMD-L Mailing List

From: Elena Lilkova (elilkova_at_phys.uni-sofia.bg)
Date: Tue Feb 10 2015 - 08:36:35 CST

Sorry,

I just now realized that the charge groups in FFTK have nothing to do with
the topology charge groups. Please, ignore my previous massage.

Sorry once again,

Elena

> Dear FFTK experts,
>
> I am trying to parameterize sulfamic acid anion (NH2SO3-) using FFTK. I
> want to put all the atoms in one charge group. But when I try to run a
> charge optimization with this charge group I get the following error:
>
> can't use empty string as operand of "-"
> can't use empty string as operand of "-"
> while executing
> "expr {[lindex $y 1]-$T*log(rand())}"
> (procedure "simulated_annealing" line 30)
> invoked from within
> "simulated_annealing $T "
> (procedure "::Optimize::Opt0::handle" line 202)
> invoked from within
> "$opt start"
> (procedure "::ForceFieldToolKit::ChargeOpt::optimize" line 424)
> invoked from within
> "::ForceFieldToolKit::ChargeOpt::optimize"
> (procedure "::ForceFieldToolKit::gui::coptRunOpt" line 55)
> invoked from within
> "::ForceFieldToolKit::gui::coptRunOpt "
> invoked from within
> ".fftk_gui.hlf.nb.chargeopt.runOpt invoke "
> invoked from within
> ".fftk_gui.hlf.nb.chargeopt.runOpt instate {pressed !disabled} {
> .fftk_gui.hlf.nb.chargeopt.runOpt state !pressed;
> .fftk_gui.hlf.nb.chargeopt.runOpt in..."
> (command bound to event)
>
> When I split the molecule in 2 or more charge groups, the optimization
> starts normally.
>
> Elena Lilkova
>
> elilkova_at_phys.uni-sofia.bg
>
> PhD student,
> Atomic Physics Department,
> Faculty of Physics,
> University of Sofia "St. Kliment Ohridski"
>
> 5 James Bourchier Blvd.
> 1164 Sofia,
> Bulgaria
>