Subject: Wigner's theorem

From: Pedro Salvador <[email-masked]>
Date: Tue, 05 Nov 2002 13:17:43 +0100

Dear CCLers,

I'm looking for demonstrations of Wigner theorem in Perturbation Theory,

namely, how energy corrections up to orders 2n and 2n+1 can be
_exactly_ obtained from n-th order eigenfunction corrections.
Can some of you point me to proper references?
I will summarize responses.

Thanks in advance!

Emili Besalu
[email-masked]
Institute of Computational Chemistry
University of Girona. Spain