On Jan 25, 2008, at 5:02 PM, Lorenzo Paulatto wrote: > > On Fri, January 25, 2008 14:30, Lazaro Calderin wrote: >> Those ghosts are out of the interval of -2.5 to 0 Ry which one would >> expect to be the important one for the bonding in this case. > > This is an optimistic assumption; in my modest experience I have found > that a ghosts at E < E_atomic_state always breaks the potential, at > E < 1 > Ry usually breaks it, and at E < 5~6 Ry causes erratic and slow > convergence. > > Try to test it in pw in a single atom configuration: it may > converge fine > as long as you start from atomic wavefunctions. But if you start > with some > random wavefunctions it converge slowly to a deeper "haunted" > configuration.
that's the fault of the Ritz's variational principle, boys! SB --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20080126/cc026399/attachment.htm
