Dear All,
Sorry for my mistake of previous email! It should be Ry I used.
As I am using the ev.x to fitting EOS on Pd. I got the wrong bulk modulus. Here
is my procedure. Please help me check what’s wrong with my fitting? input data
in Å and Ry.3.7351 -1.4555130983.8129 -1.50418463.8907 -1.5271849093.9685
-1.5303347154.0463 -1.518198834.1241 -1.4945274 Lattice parameter or
Volume are in (au, Ang) > Ang Assuming Angstrom Enter type of bravais
lattice (fcc, bcc, sc, noncubic) > fcc Enter type of equation of state :
1=birch1, 2=birch2, 3=keane, 4=murnaghan > 2then I get the output file like
below:# equation of state: birch 3rd order. chisq = 0.3034D-10# a0 = 7.4514
a.u., k0 = 6726 kbar, dk0 = 5.51 d2k0 = -0.001 emin = -1.53118# a0 =
3.94309 Ang, k0 = 672.7 GPa, V0 = 103.430 (a.u.)^3, V0 = 15.327 A^3
##########################################################################
Lat.Par E_calc E_fit E_diff Pressure Enthalpy# Ang
Ry Ry Ry GPa
Ry#########################################################################
3.73510 -1.45551 -1.45551 0.00000 170.75 -0.43510
3.81290 -1.50418 -1.50418 -0.00000 89.34 -0.93621
3.89070 -1.52718 -1.52719 0.00001 30.14 -1.32358
3.96850 -1.53033 -1.53033 -0.00001 -12.29 -1.61843
4.04630 -1.51820 -1.51820 0.00001 -42.10 -1.83804
4.12410 -1.49453 -1.49453 -0.00000 -62.42 -1.99662~
The k0
here is 672.7GPa, it should be 180GPa more or less. And I fitted same data with
another software, it gives me 167GPa.So Please Help Me What’s Wrong With My
Fitting?Thank you!!!bestxiao _______________________________________________
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