[gmx-users] pressure for ambient water
kgp.amit at gmail.com
Mon May 17 00:04:49 CEST 2010
Since the density (1 gm/cc) and T (300 K) correspond to ambient condition,
should not the equation of state dictate a pressure around 1 atm?
On Sun, May 16, 2010 at 2:07 PM, Justin A. Lemkul <jalemkul at vt.edu> wrote:
> Amit Choubey wrote:
>> Hi Everyone,
>> I was doing MD with SPC waters and found something which i am not sure how
>> to explain.
>> I made a box of SPC water of dimension 4x4x4 nm^3 and filled with water
>> using grenbox .
>> I then did a nvt simulation at 300 K for 1 ns . I used berendsen coupling
>> and Reaction - Field for coulomb interaction. Cut off were all set to 1 nm.
>> Temperature did converge to 300 K. After this i turned of nvt and did nve
>> with RF-zero for another ns. Energy was well converged during this (RMSD <
>> 0.1 %). Temperature was also around 304 K (RMSD < 1%). But the pressure was
>> 1.1 Kilobar with a fluctuation of 20 % . I don understand this, shouldnt
>> this be around 1 bar ? Could some one suggest whats on ?
> Since an NVE ensemble employs neither a thermostat nor a barostat, I don't
> know why you'd expect that.
> Thank you,
> Justin A. Lemkul
> Ph.D. Candidate
> ICTAS Doctoral Scholar
> MILES-IGERT Trainee
> Department of Biochemistry
> Virginia Tech
> Blacksburg, VA
> jalemkul[at]vt.edu | (540) 231-9080
> gmx-users mailing list gmx-users at gromacs.org
> Please search the archive at http://www.gromacs.org/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.
> Can't post? Read http://www.gromacs.org/mailing_lists/users.php
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the gromacs.org_gmx-users