Dear Professor van de Walle,
I want to calculate the phase space of a quaternary high entropy alloy in the chemical potential range of -0.5 to 0.5 eV at 1673 K using mmaps and memc2 programs. The first line of the contents of the mc.out output file includes 1673.000000 -0.500000 -0.500000 -0.500000 -0.500000 -0.500000 0.236788 0.318426 0.179865 0.180036 0.011274 0.802579 0.006111 0.297642 0.463409 0.034750 0.035906 0.227345 0.248892 0.487857 0.297642 0.459695 0.039427 0.039427 0.234019 0.245819 0.480734 0 1.000000 0.206391 0.246715 0.429507 0.039624 0.060057 0.091635 0.016869 0.092335 0.182049 0.039135 0.059070 0.090900 0.065957 0.086152 0.203456 0.042647 0.052338 0.086179 0.064447 0.105351 0.200984 0.043062 0.049883 0.086756 0.068427 0.107760 0.193998 0.042938 0.052449 0.086499 0.058401 0.104943 0.195923.I would like to inquire about the meaning of each column of data, and if we do a quadratic phase space diagram, which columns of data need to be selected, I look forward to and thank you very much for your guidance!
As explained when you type memc2 -h:
The file mcheader.out gives the content of column of the output file.
The following abreviations are used:
T: temperature
mu(A): chemical potentials of specie A
x(A): concentration of specie A
E: energy (per active site)
Egc: grand canonical energy (per active site) , i.e., E - sum_i mu(i)*x(i)
lro: long Range Order parameter of the initial ordered phase
(=0 if initial phase is disordered)
F: Helmholtz free energy (per active site)
phi: grand canonical potential: F - sum_i mu(i)*x(i)
use_mf: flag that is 1 if mf values have been used instead of mc values
corr_n_d: the average correlations associated with each cluster
n is the number of points in the cluster
d is the diameter of the cluster
Suffixes:
_lte: obtained with low temperature expansion
_mf: obtained with mean field approximation
_mc: obtained with Monte Carlo simulations
Thank you very much for your detailed reply, which has been extremely helpful to me. Another question is: if I want to draw the phase space image of a quaternary system, such as the phase space of the CrMoNbV high-entropy alloy in your published article (Redirecting), which columns of data from the memc2 output should I select?
Looking forward and thank you very much for your reply！
Hi,
You just need the x(A) - the concentration of species. Each line in the output file gives the equilibrium composition at a set of chemical potentials, indicating one possible composition in the single-phase region. For example, in Figure 3(a), I plot a point based on the concentration in each line, and all the points collectively define the single-phase region.
Btw, I appreciate your interest in the CrMoNbV paper. If you have any questions about that work, feel free to contact me at [email protected] (sorry that email address listed in the paper is no longer valid).
Best,
Siya