Therefore, pressure-induced phases transition=(DeltaE)/(DeltaV) which DeltaE=E2-E1 ( Energy of two phases at optimized Volume) and DeltaV=V2-V1( Volume of two phases at optimized volume) Is it correct?
No. The phase transition does not happen from the optimized volume of phase 1 to the optimized volume of phase 2.
usually in paper, they find possible pressure-induced phases transition by using Gibbs data. they find difference of Gibbs energy (DeltaG) from two phases and find the pressure which in it DeltaG=0. Can you guide me how i can do that? I know Gibbs=E + PV at zero-temperature. Can you guide me how i can find data (E,P,V) for gibbs calculations in WIEN2k.
You wrote almost the answer. Calculate a few E(V) data points for the first phase, fit a Murnaghan equation of state through them (x eosfit), and you have as a result (V, E, P)-data for the studied interval (case.outputeos, case.eosfit, case.eosfitb). From this, you can easily calculated the enthalpy H=E+PV. Repeat for the second phase, and see at which pressure the two enthalpy curves intersect.
Stefaan _______________________________________________ Wien mailing list [email protected] http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/[email protected]/index.html
