Prof. Giannozzi, Thanks for your reply. Yes I also think the formula is valid only for single-atom unit cells.
I checked Ziman's textbook and it looks like there needs to be a summation over the atoms in the unit cell for a multi-atom cell. Can I assume that QE (5.0.3) implements the correct formula for multi-atom unit cell although the formula given in the user guide is only valid for a single atom cell? Thanks, Sridhar On Mon, May 19, 2014 at 1:57 AM, Paolo Giannozzi <paolo.giannozzi at uniud.it>wrote: > M should be the nuclear mass, if I remember correctly (these > formulas are valid for crystals with a single kind of atoms, > if I remember correctly) > > P. > > On Sat, 2014-05-17 at 18:02 +0530, Sridhar Sadasivam wrote: > > Dear QE users and developers, > > > > > > I am writing to ask for a small clarification in the formula that > > defines the electron-phonon coupling matrix element (Equation 1 in the > > phonon user guide: > > http://www.quantum-espresso.org/wp-content/uploads/Doc/ph_user_guide.pdf) > > > > > > What is 'M' in Equation 1? Is it the total mass of the unit cell? > > > > > > Thanks, > > Sridhar > > Purdue University > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://pwscf.org/mailman/listinfo/pw_forum > > -- > Paolo Giannozzi, Dept. Chemistry&Physics&Environment, > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140519/08c6e3de/attachment.html
