According to my understanding, core-state with tag F are valence states. AM I right? If yes then why it is taking 3P states as valence states? The valence electrons for Co are 3d7, 4s2.
You use the words 'valence electrons' in the traditional 'chemical' way as states outside the noble gas core. In the context of the DFT, the term 'valence electrons' refers to all states that are not forced to behave as in a free atom (i.e. they allow to feel the presence of the surrounding crystal).
You cannot avoid to use Co-3p as valence states with wien2k, the numerics would break down if you didn't.
Your output shows that wien2k has Co-3s and Co-3p as valence states, whereas vasp considers these as core states (i.e. they will not contribute to the EFG in vasp). Co-3s will never contribute to the EFG (spherical), whereas Co-3p could (albeit not very likely).
First consider the suggestion by Peter Blaha: make sure you have identical XC-functionals in both codes, and inspect whether all magnetic moments and the DOS and band structure pictures agree for both codes.
If that is all right, then use the procedure to which I refered in my previous post to isolate the EFG contribution of Co-3p. If that is nearly zero, I don't know what is going on. If it would be equal to the vasp-wien2k difference, then you have found the origin of your problem.
Stefaan _______________________________________________ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://email@example.com/index.html