Dear all, Since my calculation is really simple, I am not going to attach my input file here. I use the QE-3.1.1 code, and perform scf calculation using pw.x on a 64-atom cell, which has a perfect fcc structure, using only the gamma point. I obtain a stress tensor then.
Later on I use exactly the same structure and cell and cut-off's, but using cp.x to perform a damped dynamics on the electrons, keeping the atoms fixed. I also obtain a stress tensor. However, the results between pw.x and cp.x is different, apart from the difference in units. The cp.x results are generally about 5~10 GPa above that of pw.x. I find this quite confusing. Is the method of calculation of stress tensor by these two programmes different? Thank you very much for solving my doubt. -- S.H. Lee M.Phil Physics Division The CUHK Graduate School _______________________________________ ?x?????? - Yahoo! Messenger ???????]?????W?????????????????????????o???????????W?r???????????????????f???????????? http://messenger.yahoo.com.hk
