[gmx-users] (no subject)

[Justin Lemkul]

On 6/18/14, 1:04 AM, AMNINDER SINGH wrote:
> Dear
> People,
>
> I am  trying to calculate enthalpy of vaporization
> of methanol.
> Using energy
> –nmol on equilibrated methanol, E pot comes -5.005 KJ/mol.
> Then for EPot
> (gas) I got 14.405 KJ/mol.
>
> Using DHvap
> = Epot(gas) - Epot (liquid)+RT.
>
> My value
> comes around 11 KJ/mol much less than experimental value 37.43.
>
> Any idea
> where is mistake might be.
>

It looks like the subtraction you did was incorrect, so your result ends up 
being about 22 kJ/mol, assuming T = 298 K (RT = 2.478).  Is your force field 
model expected to reproduce the enthalpy of vaporization?  Where did you get the 
parameters?

-Justin

-- 
==================================================

Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 601
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441
http://mackerell.umaryland.edu/~jalemkul

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