existence of HF-SCF solutions
- From: Pablo Echenique Robba <pnique/at/unizar.es>
- Subject: existence of HF-SCF solutions
- Date: Tue, 07 Jun 2005 18:37:34 +0200
Hello everybody.
What I wanted to know is whether someone could indicate to me where
may
I find a discussion on the existence of solutions of the HF-SCF
iterative procedure. I first enumerate briefly what I know:
1) The HF equations HAVE solutions (Lieb and Simon, 1977).
2) Any solution of the HF equations is an extremal, with no indication
about its being a maximum, a saddle point or a minimum whatsoever.
3) The SCF method DOES NOT always converge. Of course, when it does
converge, the wave function that results is indeed a solution of the HF
equations. Again, with no indication about its being a maximum, a
saddle
point or a minimum.
My two questions are related to point 3:
a) When does the SCF converge?
b) How do we know, if it converged, that it did it to a minimum (and
not
to a maximum or to a saddle point)?
I would thank very much any hint to articles or books discussing this.
I
mean, further than the typical "we hope it converge because our
basis
sets and our starting point are so good".
Pablo Echenique.
--
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Pablo Echenique Robba
Departamento de Fisica Teorica
&
Instituto de Biocomputacion y
Fisica de los Sistemas Complejos
BIFI
Universidad de Zaragoza
50009 Zaragoza
Spain
Tel.: 34 976761260
E-mail: pnique/at/unizar.es
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