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$f$-elements

For $f$ elements, potentials which treat the $f$ orbitals as valence orbitals are available for La, Ce, Ac, Th, Pa U, Np and Pu. For all elements one standard version and one softer potential ( _s) is available. Whereas the semi-core $p$ states are always treated as valence states, the semi-core $s$ states are treated as valence states only in the standard potentials. For most applications (oxides, sulfides), the standard version should be used. For calculations on inter-metallic compounds the soft versions are however sufficiently accurate.

In addition, special GGA potential are supplied for Ce-Lu, in which f-electrons are kept frozen in the core (standard model for the treatment of localised $f$ electrons). The number of f-electrons in the core equals the total number of valence electrons minus the formal valency. For instance: according to the periodic table Sm has a total of 8 valence electrons (6 f electrons and 2 s electrons). In most compounds Sm, however, adopts a valency of 3, hence 5 f electrons are placed in the core, when the pseudopotential is generated (the corresponding potential can be found in the directory Sm_3). The formal valency $n$ is indicted by _n, where n is either 3 or 2. Ce$\_3$ is for instance a Ce potential for trivalent Ce (for tetravalent Ce the standard potential should be used).


next up previous contents
Next: The pseudopotential generation package Up: The PAW potentials Previous: -elements, excluding first row   Contents
Georg Kresse
2007-03-01