[gmx-users] NVE+NVE: Two groups: one with Tcouple while the other one not

[Vitaly V. Chaban]

The reason is the slow energy exchange between the gas and the solid.



On Thu, Sep 10, 2015 at 9:47 PM, Guiyuan Mo <gmo at purdue.edu> wrote:

> Okay. Thank you VV.
>
> But the simulation result show that the system temperature would go up to
> 1000K after I turned off the Tcoupl for nC12 (by setting tau_t = -1). What
> would be reasons?
>
> ------------------------------
> *From: *"Vitaly V. Chaban" <vvchaban at gmail.com>
> *To: *"gmx-users" <gmx-users at gromacs.org>
> *Sent: *Thursday, September 10, 2015 8:37:52 PM
> *Subject: *Re: [gmx-users] NVE+NVE: Two groups: one with Tcouple while
> the other one not
>
> Sure.
>
> N2 heats the large moleculle which dissipates heat much more slowly and
> does not have a thermostat to help it.
>
>
>
>
> On Thu, Sep 10, 2015 at 9:09 PM, Guiyuan Mo <gmo at purdue.edu> wrote:
>
> > Hi,
> >
> >
> > I am modelling a box with two groups of molecule: N2 and C12H26.
> > 1. Initially, NVT was used for both:
> >
> > ; Temperature coupling is on
> > Tcoupl = nose-hoover
> > tau_t = 1.0 1.0
> > tc-grps = N2 nC12
> > ref_t = 450 300
> >
> >
> > 2. Then I turned off the Tcoupl for nC12 (by setting tau_t = -1):
> >
> > ; Temperature coupling is on
> > Tcoupl = nose-hoover
> > tau_t = 1.0 -1
> > tc-grps = N2 nC12
> > ref_t = 450 300
> >
> >
> > What I expected was that nC12 was heated up by N2. However the system
> > temperature would go much higher than 450K... We know this is not true.
> >
> >
> > Does anyone can help me? Is there something wrong or needed to take care
> > when using tau_t = -1? Thanks.
> >
> >
> > Best,
> > Mo
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