On Monday 24 December 2007 12:11, oulihui666 wrote: > I intend to ask wheather I could add a extra electron and +1 charge > simultaneously?
you can add an extra electron by setting variable "nelec" to the desired charges. The code will automatically add a neutralizing background (it must! the energy of a charged supercell is infinite). In practice, the energy is calculated as usual, but the divergent terms will be calculated as if the system was neutral. For a molecule the energy so obtained will converge for increasing size of the supercell to the true energy of the charged molecule; there are various tricks to speedup the convergence (e.g. the Makov-Payne correction). Formation energies of charged defects can also be calculated but it is a more tricky business. By the way, all this has been explained 2n+1 times. Paolo -- Paolo Giannozzi, Democritos and Udine University
