[Wien] use of in1new

[Stefaan Cottenier]

> i have performed a calculation with all defaulted parameters and the
> calculation successfully converged. but i want to know if the default
> linearization energy and local orbit are correct or good enough, so i
> want to perform a calculation with a -in1new switch. i dont what
> number should i set for N, i.e. how many iterations should be taken
> before rewriting the case.in1 file. from the user mannual page 52 i
> know that if the N is not set correctly, a bad result would be listed.
> for my calculation was converged,should i set the N larger, for
> example just before the end of the calculation(that is about 19)?

Because you start already from a converged case, you can set N=1.
Usually I set N=5-10 when starting from scratch, and switch to smaller
values (N=2-3) once moderate convergence has been reached. The large
values in the beginning prevent getting crazy linearization energies
(and subsequent divergence) obtained from the still very much
oscillating solutions in the beginning of the scf cycle. But once
convergence has set in, the linearization energies will not change very
much any more, and it does not harm to update them every 2-3 iterations.

If you don't want to interrupt your scf-cycle to change N, then start
with N=5 from the beginning. It works almost always.

Stefaan


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