[Pw_forum] Problem with nbnd in clusters

[Stefano de Gironcoli]

let me add one reference I find (not completely ir-)relevant in this 
context: Volker Bach <http://prola.aps.org/search/field/author/Bach_V>, 
Elliott H. Lieb <http://prola.aps.org/search/field/author/Lieb_E_H>, 
Michael Loss <http://prola.aps.org/search/field/author/Loss_M>, and Jan 
Philip Solovej <http://prola.aps.org/search/field/author/Solovej_J_P>, 
"There are no unfilled shells in unrestricted Hartree-Fock theory " 
Phys. Rev. Lett. 72, 2981 - 2983 (1994) [ 
http://link.aps.org/abstract/PRL/v72/p2981]
where they demonstrate (in 1994 not in 1930) that in the case of 
unrestricted HF (which means allowing symmetry breaking wfc's) one never 
gets problems of anomalous or partial filling of shells... DFT is not HF 
but I would expect something qualitatively similar.
stefano