[gmx-users] "Sign convention" g_energy total energies
jalemkul at vt.edu
Thu Aug 15 00:50:50 CEST 2013
On 8/14/13 6:42 PM, gg jj wrote:
> Hi everybody.
> I wonder how the "sign convention" of GROMACS (or better g_energy ) is: Is
> U(state_i):= <E_tot (state_i)>_t correct or do i have to choose the other sign
> U(state_i)= -1.0* <E_tot (state_i)>_t ? (<>_t denotes the time average)
> I need the correct sign for further calculations since i need to add something
> (-T\Delta S) to the difference of the inner energy of two states: \Delta
> F=\Delta U -T\Delta S (for T=const)
There is no need to manipulate the sign. It's not even a Gromacs convention,
it's standard. Negative energy = net attraction, positive energy = net repulsion.
Justin A. Lemkul, Ph.D.
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
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