[Pw_forum] about choosing density for solving scf

[Paolo Giannozzi]

On Apr 15, 2007, at 12:24 , Amin Babazadeh wrote:

> For solving the self-consistent equation in Kohn-Sham method
> we need to select an ordinary (random) density to start the solving
> equation.

not necessarily: the default starting charge density is obtained
from a sum of atomic (pseudo-)charges, stored in the
pseudopotential files. A random starting density is, well,
random, just normalized to yield the prescribed total charge.

> i want to know in espresso how this density choose?

"how is this density chosen" or " how to choose this density"?

Paolo
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Paolo Giannozzi, Democritos and University of Udine, Italy