On Sep 29, 2006, at 13:31 , li quan wrote: > Dear Polo, > Thanks for your and others' answers, you say that > >electron-phonon coefficients are seto to zero > > for phonons whose frequency is smaller than 20 cm^-1 > > But, if I want to get the value of electron-phonon coefficients for > phonons whose frequency is smaller than 20 cm^-1. What should I do? > Could I reduce the value of "eps"?
the idea behind the cutoff at 20 cm^-1 is to get rid of acoustic phonons at q=0 (whose contribution to the el-ph coupling is zero anyway). If you have "real" phonons with frequency < 20 cm^-1 , you may try to reduce the value of eps, but I guess it will be hard to get an accurate value. Paolo
