# Accession Number:

## AD0620056

# Title:

## PERTURBATION THEORY OF THE SELF-CONSISTENT FIELD

# Descriptive Note:

## Technical rept.

# Corporate Author:

## HARVARD UNIV CAMBRIDGE MA DIV OF ENGINEERING AND APPLIED PHYSICS

# Personal Author(s):

# Report Date:

## 1965-05-26

# Pagination or Media Count:

## 22.0

# Abstract:

A perturbation theory of the self-consistent field is developed using a Greens function method after the manner of Peng. It is shown that a self- consistent perturbation theory yields the same answers as the conventional random phase approximation. The equivalence of the perturbation approach to spin waves in metals developed by Herring and the random phase approximation for the same problem is seen to be an example of this. The effect of the weak periodic field on a Hartree-Fock electron system is here explicitly done both by the perturbation approach and the random phase approximation with the Greens function approach. The Greens function approach is finally generalized so as to include, in principle, correlations beyond the Hartree-Fock.

# Descriptors:

# Subject Categories:

- Numerical Mathematics