How to calculate the enthalpy under different pressure

[bahadir.altintas]

I need to calculate enthalpy for a system under various pressure between 0 to 600Gpa. I can optimize the systems under different pressures, but how can i calculate/get enthalpy of each system to plot enthalpy-pressure relation.

is it available at somewhere in output file of the optimizatim?

thanks

[jzwanzig]

Can't you just add it by hand? I mean, given that H = U + pV, where U is the internal energy of the unit cell (etotal in the abinit output), p is your target pressure, and V the unit cell volume (ucvol in abinit output), can't you just calculate the pV contribution? (be sure to use consistent units, ucvol is in atomic units, therefore Bohr^3).

[bahadir.altintas]

thank you for reply,

that is what i did yesterday but i though that could be an output gives for enthalpy. but i calculated greping volumes and pressures and Total energies from the outputs with the general enthalpy formula above.

bahadir