Dear M Alaii Please provide always your affiliation when posting.
> I was wondering whether there is a way to guess what the edge of conduction > band is by the Fermi level that the software provides. It depends on the system. In the case of an insulator or semiconductor you should draw a reasonable band structure and compare with it the Ef value given by the code. You can always try to fill the bands by hand with the correct amount of electrons... In the case of insulating isolated systems (i.e., molecules) the LUMO orbital is just the first above the given Ef at gamma. In the case of metals or semimetals you should find that the Ef value crosses (one of) the bands. Of course you should also calculate a given number of unoccupied eigenstates, either by using a nbnd value greater than nelec/2, or by using some smearing scheme. Remember that enegy gaps (or HOMO-LUMO gaps) are affected by a static correlation error when using LDA or GGA approximations, so they often compare badly with optical gaps. HTH Giuseppe -- ******************************************************** - Article premier - Les hommes naissent et demeurent libres et ?gaux en droits. Les distinctions sociales ne peuvent ?tre fond?es que sur l'utilit? commune - Article 2 - Le but de toute association politique est la conservation des droits naturels et imprescriptibles de l'homme. Ces droits sont la libert?, la propri?t?, la s?ret? et la r?sistance ? l'oppression. ******************************************************** ? ?Giuseppe Mattioli ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?CNR - ISTITUTO DI STRUTTURA DELLA MATERIA ? ? ?v. Salaria Km 29,300 - C.P. 10 ? ? ? ? ? ? ? ? ? ?I 00015 - Monterotondo Stazione (RM) ? ? ? ? ? ? ?Tel + 39 06 90672836 - Fax +39 06 90672316 ? ? ? ?E-mail: <giuseppe.mattioli at ism.cnr.it>
