A new nonperturbative theory of core-hole ionizations: a compact cluster-expansion technique for treating relaxation effects

✍ Scribed by Debasis Mukhopadhyay Jr.; Rajat Chaudhuri; Debashis Mukherjee

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 655 KB
• Volume: 172
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(90)80149-8

✦ Synopsis

We have introduced in this paper a new cluster-expansion ansatz for the waveqerator P that incorporates orbital relaxation and differential correlation effects in a compact and efficient manner. The ansatz utilizes a Thouless-type transformation inducing these effects via a seminormal ordered exponential-type cluster operator, denoted as exp,[ Tt F+F],

with T, SC and S as the core-correlation, valenceuwrelation and relaxation-cumdifferentiakorrelation cluster operators, respectively. The theory is illustrated by using tbe example of one-valence core ionizations. Numerical applications illustrate both the superiority of the method to the normal-ordered ansatz for Q and the relative unimportance of SC for this problem.