Dear Sudha, One expects that all the pseudopotentials lead to the same electronic structure that an all-electron calculation. Small numerical differences are expected. This page is useful https://molmod.ugent.be/deltacodesdft for better understanding You should test that the density of states or the bands, are "the same" computed with both sets of peudopotentials. There will be small numerical differences. You should also check the lattice parameteres. Variations smaller than 1% (using the same xc functional) are reasonable. To compute optical properties with the NC you may use the relaxed structure obtained either with USPP or with NC. Small numerical differences are also expected and are acceptable. Care is needed if the differences become qualitative. If you use the USPP structure, with NC the same strusctire is stressed, and the stress and cause splitting of some levels and some peaks in the optical properties. Best regards Eduardo
--------- Mensaje reenviado ---------- From: Sudha Priyanka <[email protected]> To: PWSCF Forum <[email protected]> Cc: Bcc: Date: Fri, 12 Jan 2018 04:25:20 -0800 Subject: [Pw_forum] Shall we calculate some of the parameters by USPP and some other properties by norm conserving PP for same compound? Dear Experts, I did scf and other calculation by using USPP, but in epsilon calculation (optical properties) I have no option but have to use only norm conserving PP, Is this correct? Will it make any difference? Shall I compare the calculated properties and parameters by using these different pseudopotentials? For example, If I have calculated electronic properties by USPP and optical properties by norm conserving PP, can I do interpretation of these properties for the same compound? With warm regards Sudha Priyanka G Assistant Professor, Lady Doak College, Madurai, Tamilnadu, India.
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