Dear Fariba, The Kohn-Sham (please, not kohen) orbitals produced by pp.x are not orthonormalized in general, because of the pseudo-potentials and projection techniques (PAW). However, practically, you may safely assume they are orthogonal and almost normalized (self-overlaps are not far from 1.0). This is especially true for norm-conserving PP (by construction, the wavefunctions supposed to preserve norm), and, in slightly smaller extent, for ultra-soft pseudopotentials. For PAW wavefunctions the trick is to reconstruct full wavefunction from the projection, so it is S|psi>. If i remember it correctly, the ortogonality will then be for <psi_i|S|psi_j> = delta_ij. However you can obtain S|psi> with pp.x as well as |psi>. Please anyone correct me if i'm wrong at some point.
Thank you, Alexey ----- Original Message ----- From: [email protected] To: "PWSCF Forum" <pw_forum at pwscf.org> Sent: Tuesday, August 28, 2012 6:23:31 AM Subject: [Pw_forum] kohen -sham orbitals ortogonality and ortonormality Dear All, Would you please let me know if the kohen -sham orbitals ,which are obtained by pp.x, are normalized, orthogonalized or orthonormalized? Regards Fariba Nazari IASBS -- This message has been scanned for viruses and dangerous content by MailScanner , and is believed to be clean. _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum -- Dr. Alexey V. Akimov Postdoctoral Research Associate Department of Chemistry University of Rochester aakimov at z.rochester.edu
