[gmx-users] Fwd: Different Cv and Cp

[Faezeh Pousaneh]

Dear Andre,

The heat capacity of liquids at constant pressure is approximately the same
as heat capacity at constant volume. From my simulations they are different
around 50 j/mol.K, that is too much.


Best regards


On Mon, May 25, 2015 at 2:44 PM, André Farias de Moura <moura at ufscar.br>
wrote:

> they have to be different since they stand for different heating processes,
> you really need background reading on basic thermodynamics.
> Andre
>
> On Mon, May 25, 2015 at 6:59 AM, Faezeh Pousaneh <fpoosaneh at gmail.com>
> wrote:
>
> > Hi,
> >
> > I do not know why I obtain two difference cp and cv from NVT and NPT
> > simulations.
> > What I do is, I take 1000 lutidne molecules, and I do firstly an energy
> > minimization with steep integrator, then NPT simulation at T=300 and P=1
> > atm for 10ns, (I obtain Cp= 230), then I run NVT for 10 ns with same mdp
> > file except no pressure coupling, and with initial .gro file obtained
> from
> > NPT run, (I obtain Cv=180).
> > Does some one know where is my mistake? (In both runs, I obtain Cv and Cp
> > from g_energy and in different time intervals and after equilibrited
> time)
> >
> >
> > Best regards
> > --
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> --
> _____________
>
> Prof. Dr. André Farias de Moura
> Department of Chemistry
> Federal University of São Carlos
> São Carlos - Brazil
> phone: +55-16-3351-8090
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