[Pw_forum] spilling parameter in Lowdin - how to assign the charge that went into Nirvana ?

[Paolo Giannozzi]

On Mar 24, 2007, at 15:54 , Andrea Ferretti wrote:

> Lowding orbitals in Quantum-Espresso (at least as far as I know) are
> computed from the atomic reference states from pseudopotential data
> according to:
>
> S_ij = < i | j >      are the overlaps of atomic orbitals i and j
>
> lowding orbitals are then obtained as
> | low_i > =  R_ij  | j >
>
> where  R = S^{-1/2}
>
> so I think there is no optimization (in the sense of the paper above)
> but maybe I am missing something

no, you aren't missing anything: the atomic basis is not optimized

Paolo
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Paolo Giannozzi, Democritos and University of Udine, Italy