In data 27 agosto 2009 alle ore 10:33:06, Bertrand SITAMTZE <siyouber at yahoo.fr> ha scritto: > I wanted to use the Li.pw91-s-van_ak.UPF. But, as we all know, this has > to be tested.
Normally pps from the quantum-espresso page have already been tested, and often used in some published work. Yet, doing some extra testing is always a good idea. > That is why I decided to generate a pseudopotential by myself. Do you > know about this regeneration process? A good point to start to generate a new pp is an old one. At the begging of the UPF file there is a short human-readable section where you can find most of the parameters used to generate the file. The reference energy for the second projector are actually missing, but you can usually find them easily. > I used the default value From the manual: If not specified, the matching radius is determined by the condition: rho_core(rcore) = 2*rho_valence(rcore) in you specific case it is probably too small. Furthermore, the pp you are trying to imitate includes the 1s electrons in valence: it is practically an all-electron pseudopotential. Hence, it has no core charge. Generating a pseudopotential for Lithium with only the 2s electron in valence, using core-charge correction, can be quite difficult; furthermore the result won't probably be very accurate. Nevertheless, it will also be much softer (it requires a much lower cutoff). best regards -- Lorenzo Paulatto SISSA & DEMOCRITOS (Trieste) phone: +39 040 3787 511 skype: paulatz www: http://people.sissa.it/~paulatto/ *** save italian brains *** http://saveitalianbrains.wordpress.com/