ABINIT Discussion Forums

Dear all,
I want to calculated elastic and vibrationall properties of sr s1-x ox alloys, I have not sure to using VCA for this compounds because high LO-TO spliting for SrS (100 cm-1) and SrO (260 cm-1) and high born effective charge, so I don’t know which condition for using VCA.
Thanks

Chemically, sulfur and oxygen are not very similar so I see no reason why VCA would give good results in this system. But VCA is not a "rigorous theory" which means you should find a well-understood model system including S and O and test the approximation.

Dear Prof:
Thank you very much for your help .

Best regards.