[gmx-users] pressure dependence on volume.

[Tsjerk Wassenaar]

Hi Johnny,

The density is M/V. The only parameter changing with pressure coupling is
V, so the density and volume are fully correlated. No surprise there.

Cheers,

Tsjerk
On Oct 19, 2014 2:27 AM, "Johnny Lu" <johnny.lu128 at gmail.com> wrote:

> The frames with density closest to the average density also have volumes
> closest to the averaged volume.
>
> On Sat, Oct 18, 2014 at 8:18 PM, Johnny Lu <johnny.lu128 at gmail.com> wrote:
>
> > I searched the energy file made by g_energy, and found that NPT frames
> > with very similar densities have very similar volume.
> >
> > So, I guess using density is same as using volume in this case.
> >
> > On Sat, Oct 18, 2014 at 9:09 AM, Johnny Lu <johnny.lu128 at gmail.com>
> wrote:
> >
> >> Would manually setting the box size make vacuum bubbles?
> >>
> >> On Sat, Oct 18, 2014 at 9:08 AM, Johnny Lu <johnny.lu128 at gmail.com>
> >> wrote:
> >>
> >>> my bad. that formula for density is wrong. But I till don't see why
> >>> using the same averaged density (instead of volume) for the NVT and NPT
> >>> simulations would give a different result.
> >>>
> >>> On Sat, Oct 18, 2014 at 8:52 AM, Johnny Lu <johnny.lu128 at gmail.com>
> >>> wrote:
> >>>
> >>>> Was the density calculated by # particles /  volume ?
> >>>>
> >>>> If so, using volume (as I did), and using density would give the same
> >>>> wrong pressure, upon transitioning from NPT to NVT.
> >>>>
> >>>
> >>>
> >>
> >
> --
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