[Wien] E/V problem with gamma-Ce

[fa kh]

Dear Wien2k users:
We are running WIEN2k_07.2 version and trying to obtain equilibrium volumes for both isostructural alpha and gamma phases of Ce crystal, which their structure is fcc.
For alpha phase which its experimental lattice parameter is equal to 9.16517 bohr, we applied GGA approximation and obtained a good E/V curve and thereby a good lattice parameter compared to the experimental value. But unfortunately for the gamma phase which its lattice parameter is 9.75477 bohr, we are not successful. We applied GGA and LDA+U approximations, but the results of GGA and LDA+U optimizations are increasing straight lines. Thus there is no any minimum point, and the eosfit program cannot yield a reasonable lattice parameter for the gamma phase. 
This is in the case that the equilibrium volume for the gamma cerium was previously reported using LDA and GGA [PRL74, 2335 (1994)] and LSDA+U [PRB 59, 3450 (1998)]. We dont know what is the problem, and do appreciate any comments from you.
We considered number of k-points =7000, mixing factor=0.001 and R_MT=2 bohr.
Your,
F. Kheradmand



 
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