The use of phase equilibrium calculations to compute physical properties of rocks has become commonplace in geophysical modeling. Typically, the phase equilibrium calculations are used to construct two-dimensional tables of rock properties as a function of pressure and temperature. Phemgp is a Fortran program that can be used to assemble a three-dimensional table that accounts for compositional variations from two-dimensional tables. See Zunino et al., 2011.
A quick guide on how to generate tables to be used with Phemgp is available at http://www.perplex.ethz.ch/phemgp/phemgp.html . Two tables representing harzburgitic and basaltic end-members are provided here as an example.
Zunino, A., J. A. D. Connolly, and A. Khan (2011), Precalculated phase equilibrium models for geophysical properties of the crust and mantle as a function of composition, Geochem. Geophys. Geosyst., 12, Q04001, doi:10.1029/2010GC003304
Compile Phemgp using a Fortran compiler. For instance, with the GNU Fortran compiler, do:
gfortran phemgp_0.5.f90 -o phemgp.x
On Linux or MacOS run it with:
./phemgp.x
In order to use Phemgp with the tables generated from Perple_X output (as described in http://www.perplex.ethz.ch/phemgp/phemgp.html) the user must add a line containing the basalt fraction in the header of the table.
The line specifying basalt fraction (as a floating point number) has to be placed after the row containing the title of the table (e.g., "hzmb_200_1.phm"), as shown by the following example (basalt fraction=0.2):
Header of the table obtained from Perple_X:
|6.6.6
hzmb_200_1.phm
2
T(K)
500.002000000000
40.8162448980000
50
P(bar)
1.13999900000000
2857.11673473755
modified header:
|6.6.6
hzmb_200_1.phm
0.2d0 !! <<=== here
2
T(K)
500.002000000000
40.8162448980000
50
P(bar)
1.13999900000000
2857.11673473755