On Oct 22, 2011, at 19:25 , chengyu yang wrote: > At first I used ultrasoft potential for both cu and cnt, > but the result is about -1.6 ev, much different from > around -0.1 ev in the literature. > Then I changed the potential to PAW potential, > for that is what's used in the literature
you also changed from LDA to PBE. It's not a minor difference, especially if the bonding is weak. Why don't you try a few simpler systems to start with? P. --- Paolo Giannozzi, Dept of Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
