Computer Physics Communications Program Library

Programs in Physics & Physical Chemistry



Manuscript Title: Analytic exchange integral for coupled cluster theory in the homogeneous electron gas
Authors: Claudine Gutlé
Program title: qexm2em1
Catalogue identifier: ADXJ_v1_0 Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 174(2006)836
Programming language: Mathematica 4.0 (due to versions incompatibility the program does not work with more recent versions like Mathematica 5.1).
Computer: Created using a PC, but can be run on UNIX machines.
Operating system: Linux.
RAM: 151 Mb
Keywords: electron gas, analytic integrals, exchange diagrams, correlation energy.
PACS: 71.10Ca.
Classification: 5.
Nature of problem: The program gives an analytical derivation of a six-dimensional exchange integral involved in the calculation of the correlation energy of the electron gas.
Solution method: Changes of variables were gradually introduced in order to decrease the dimensionality of the integral, and eventually an analytical expression was obtained.
Restrictions: The present version of the program has been designed only for calculating only one integral. Though, the method can be used for other cylindrically-symmetric integrals.
Running time: file formula.nb less than 1s; qexm2em1.nb: 02mn 02s; qexm2em1qinf2AA.nb: 09mn 42s; qexm2em1qinf2BB.nb: 08mn 05s; qexm2em1qinf2AB.nb: 00mn 43s; qexm2em1qsup2.nb: 23mn 26s on 1 GHz machine.