>If you are computing enthaply in the NPT ensemble, P is constant, and >is the applied pressure.
>The "pressure" quantity calculated from the KE and the virial is not >the pressure. It is a quantity that when averaged over time is equal >the pressure. Only the average is meaningful macroscopically. Right, that's an easy one to miss but i don't think that's my problem here. >If you are computing enthalpy in another ensemble (which is possible, >though it may be harder to interpret) then you would use the average >pressure from this quantity I'm running in NPT and was calcaulating H from ave. P, ave. U and ave. V for the run while i understand that this doesn't exactly equal average H it should be close enough for me at this point, going back and redoing it with P set to the reference value (which the average hits with small fluctuations) the resultant H still doesn't line up properly for some example data: "pV, g_energy" V, m^3 pV, J pV, kJ/mol 442.42 1.46E-26 1.46E-18 884.07 P = 1000 bar = 100,000,000 Pa and i see that my pV is around 2x g_energies pV, no values are scaled for the # of items in the box at this point, this is all for moles of the system i think that's alright though -- View this message in context: http://gromacs.5086.x6.nabble.com/Enthalpy-Confusion-tp5009053p5009062.html Sent from the GROMACS Users Forum mailing list archive at Nabble.com. -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! * Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists