how to calculate thermodynamics properties of mixture using vasp simulation results

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lqzhang · #1 Post by **lqzhang** » Sat Apr 11, 2009 9:06 pm

Dear VASP administer:

Based on vasp simulation results, I like to calculate the thermodynamics properties of mixture: sio2+mgo melts.

I should use H=E+PV, here H is enthalpy, E is the total energy, P and V are the pressure and volume of system. From OSZICAR file output, there is a E, which is the total free energy. Could I use that to calculate the enthalpy of system ? Thanks a lot.

The second question is that, in doing the VASP simulation for 6 ps, I could see the E could have abrupt increase. Why that could happen and what does that mean? Is that a sign that the simulation was not stable? Thanks a lot.

lqzhang · #2 Post by **lqzhang** » Tue Apr 28, 2009 3:24 pm

since nobody answered my question up to now, I will ask a different question. What kind of sampling method is used in VASP? I know that in LAMMPS molecular dynamics simulation, the sampling is based on Bolzman's distribution. I really could not find answer from the available website. Thanks a lot.