Dear All, A small question to those of you with expertise in phonon calculations of ionic crystals.
I understand that in bulk calculations the dynamical matrices at small q are split into analytic and nonanalytic parts, with the latter accounting for the effects of macroscopic electric field. However, if we want to study phonons in a model representing an electroded thin film instead of a bulk crystal (i.e., the electrodes are not explicitly included in such a calculation), we should assume that such an electric field will be screened out by the free charges and its influence onto ionic vibrations should not be considered. I am under an impression that to achieve this in pwscf I need to block the calls to nonanal(...) subroutine in dynmat and matdyn, while leaving everything else intact. Would this work out or could it possibly be not as trivial as I imagine it? Would appreciate your comments, Serge -- ********************************************************* Serge M. Nakhmanson phone: (630) 252-5205 Assistant Scientist fax: (630) 252-4798 MSD-212, Rm. C-224 Argonne National Laboratory 9700 S. Cass Ave. Argonne, IL 60439 *********************************************************
