I have calculate band gap of Sr_xCa_1-xWO_4 alloys by using VCA.
i have correctly obtained band gap of CaWO4, Sr0.25Ca0.75Wo4, Sr0.25Ca0.75Wo4, Sr0.5Ca0.5Wo4, Sr0.75Ca0.25Wo4. But energy gap SrWO4 is wrong (band gap SrWO4 must be direct while i have obtained indirect
), when i calculated band structure and energy gap of SrWO4 without VCA , i got direct band gap and value energy gap is in agreement with that in value of experimental. I have attached two input files of band structure. Where is my problem?Best regards,
Narges
