[Pw_forum] question on electron_dynamics and orthogonalization

[Nicola Marzari]

Thanks.

> I will play with it a bit more to see if I can isolate the problem. I
> do recall that the stress changes on the order of 0.5 GPa per
> component when I changed either
> emass_cutoff
> or
> nr1b,nr2b,nr3b
> 

The only reason while it would change with emass_cutoff is that
you are not perfectly converged (I think). With enough iterations,
emass_cutoff shouldn't matter; it is just a preconditioning to take
into account that the hamiltonian is diagonally dominanant, in a plane
wave basis set, with the diagonal diverging as G^2.

nr1b... etc: well, let's revisit this as soon as CP is fixed. Paolo
and Carlo have been kindly working on this.

			nicola


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