[Pw_forum] Re: a question about a calculation on a relatively large system

[umari at democritos.it]

Dear Peter,

I would suggest for checking pw.x the option
diagonalization='cg', in this way a conjugate-gradient
algorithm is used for finding  the ground-state of the
KS-Hamiltonian, instead of the 'davidson' algorithm.
It will be slower but maybe more stable.

The main difference between the cp.x and pw.x (at gamma-point)
codes is that cp.x minimizes directly the total energy avoiding
charge-mixing. This could turn into more stability in case of
large systems.


Paolo

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