Energy in eV are wrong stefano (sent from my phone)
> On 20 Apr 2015, at 18:31, Xiao <[email protected]> wrote: > > Dear sir/madam, > > 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 ev. > > 3.7351 -1.455513098 > 3.8129 -1.5041846 > 3.8907 -1.527184909 > 3.9685 -1.530334715 > 4.0463 -1.51819883 > 4.1241 -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 > 2 > then 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!!! > > best > xiao > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum
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