Dear all,
I recently evaluated with PW the binding energy of a O2 molecule using the regular ultra-soft PP from the webpage. I noticed that the energy obtained could be 5.7eV or 6.7eV depending if the flag "nosym=.true." is used or not in the energy evaluation of the isolated oxygen atom. I would like to know if anyone could help me understand why such a large difference is obtained for this system, since for many other systems (such as metals) the inclusion of "nosym=.true." for the isolated atom do not affect so much (or not at all) the value of the binding/cohesive energy. Thanks very much for your time, and all best for all! Fabio Negreiros IPCF - CNR, Pisa - Italia -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101203/3cd7d50d/attachment-0001.htm -------------- next part -------------- A non-text attachment was scrubbed... Name: O2-iso.scf.in Type: application/octet-stream Size: 730 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20101203/3cd7d50d/attachment-0008.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: O2-iso.scf.out Type: application/octet-stream Size: 43953 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20101203/3cd7d50d/attachment-0009.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: O2_nosym-iso.scf.in Type: application/octet-stream Size: 730 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20101203/3cd7d50d/attachment-0010.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: O2_nosym-iso.scf.out Type: application/octet-stream Size: 41811 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20101203/3cd7d50d/attachment-0011.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: O-iso.scf.out Type: application/octet-stream Size: 32895 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20101203/3cd7d50d/attachment-0012.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: O-iso.scf.in Type: application/octet-stream Size: 656 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20101203/3cd7d50d/attachment-0013.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: O_nosym-iso.scf.in Type: application/octet-stream Size: 656 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20101203/3cd7d50d/attachment-0014.obj -------------- next part -------------- A non-text attachment was scrubbed... Name: O_nosym-iso.scf.out Type: application/octet-stream Size: 13042 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20101203/3cd7d50d/attachment-0015.obj
