[gmx-users] temperature effect on potential energy

[Mark Abraham]

On 4/21/2011 11:37 PM, Juliette N. wrote:
>
>
>         I have a quick enquiry whether temperature affects pontetial
>         energy
>         terms. Does T is accounted for to parametrize OPLS FF? Do
>         bonded and
>         nonboded energies vary with T?
>
>     Have you tried?
>     Try to read up on heat capacity.
>
> Hi David,
>
> Yes it affects potential. My question is whether this dependence is 
> accounted for in parametrization (k constants in harmonic potentials..)

The generated parameters have no explicit T-dependence, so the functions 
in which they appear do not have T-dependence either.

If you want to know how a force field was parametrized, then there's no 
substitute for getting the literature and reading it.

> or it affects say nb interactions in the sense that at higher T 
> particles move around faster and it might be that LJ does not attract 
> molecules as it would at lower T.

AFAIK, the physical interactions modelled by the LJ potential are not 
dependent on particle velocities, so why should the LJ "not attract 
molecules" at higher T? Something moving faster doesn't mean it's less 
attracted to things that it would be attracted to when traveling 
slower... gravity doesn't magically suspend for an aeroplane...

Mark

>
>         Thanks,
>         Jennifer N.
>
>
>
>     -- 
>     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 <mailto:spoel at xray.bmc.uu.se>
>     http://folding.bmc.uu.se
>     -- 
>     gmx-users mailing list gmx-users at gromacs.org
>     <mailto:gmx-users at gromacs.org>
>     http://lists.gromacs.org/mailman/listinfo/gmx-users
>     Please search the archive at
>     http://www.gromacs.org/Support/Mailing_Lists/Search before posting!
>     Please don't post (un)subscribe requests to the list. Use the www
>     interface or send it to gmx-users-request at gromacs.org
>     <mailto:gmx-users-request at gromacs.org>.
>     Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>
>
>
>
> -- 
> Thanks,
> Jennifer N.
>




-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://maillist.sys.kth.se/pipermail/gromacs.org_gmx-users/attachments/20110422/0441eeee/attachment.html>