Good evening, I have 2 questions about mixing_beta.
1.) The manual states that mixing_beta is a mixing factor for self-consistency. Can someone give a reference to how this is defined, mathematically? 2.) I have been able to divine from the forums that it is effectively a scaling of of the previous SCF cycle's density (http://www.mail-archive.com/pw_forum@pwscf.org/msg01302.html) as it relates to the current step's calculation. I appreciate that it improves SCF convergence. Broadly, I am confused why this would be useful to speed up SCF convergence. I have written my share of SCF codes for molecules with basis functions of (gaussians+spherical harmonics), but am new to plane waves and PBCs. In molecular calculations, one never scales the previous step's density in an iterative solution (or in solving non-linear coupled cluster amplitudes). Is this somehow akin to DIIS histories, in some way, to be selective in the previous cycle's estimate? Thank you for your time, Dr. Robert Molt Indiana-University Perdue University ENSCO _______________________________________________ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum