Computer Physics Communications Program Library

Programs in Physics & Physical Chemistry

PROGRAM SUMMARY

Manuscript Title: A program of generation and selection of configurations for the configuration interaction method in atomic calculations SELECTCONF.
Authors: P. Bogdanovich, R. Karpuskiene, A. Momkauskaite
Program title: SELECTCONF
Catalogue identifier: ADWD
Journal reference: Comput. Phys. Commun. 172(2005)133
Programming language: FORTRAN 77.
Computer: Any computer with a FORTRAN 77 compiler.
Operating system: Linux.
RAM: 4 MB
Keywords: Complex atoms, Configuration interaction, Admixed configurations, Second order of perturbation theory.
PACS: 31.25.Eb, 31.25.Jf.
Classification: 2.1, 2.9.
Nature of problem: Due to the restricted possibilities of the computers and codes, which are employed, the practice of CI requires one to select and superimpose those configurations the usage of which happens to be the most effective. This program is designed for the selection of such admixed configurations.
Solution method: All admixed configurations possible in the specified basis set of radial orbitals (RO) are constructed using the one-electron and two-electron virtual excitations. Then the averaged evaluation of their influence on the energy or wave function of the adjusted configuration is performed in the second order of perturbation theory. The results of this evaluation are used for the selection of admixed configurations.
Restrictions: In the present version of the program the number of passive shells is restricted by MIUZ=20; the number of active shells by MIAT=10; the number of generated admixed configurations, by MECO=10000; the number of RO used, by MOR=MRO=99. All these limitations are not hard-coded and can be changed by substituting the values of the corresponding parameters.
Unusual features: The possibility of carrying out the averaged evaluation of the influence of admixed configurations in the second order of perturbation theory and to perform their selection on this ground.
Running time: Several seconds. This time depends on the size of the problem; the computation time depends approximately linearly on the number of possible admixed configurations, which increases rapidly with a growing number of active shells and an extending RO basis set.
References:
[1]	C. Froese Fischer, Comput. Phys. Commun. 43 (1987) 355.
[2]	P. Bogdanovich, R. Karpuskiene, Comput. Phys. Commun. 134 (2001) 321.
[3]	R. Karpuskiene, R. Karazija, P. Bogdanovich, Phys. Scripta, 64 (2001) 333.
[4]	C. Froese Fischer, B. Liu, Comput. Phys. Commun. 64 (1991) 406.
[5]	P. Bogdanovich, A. Momkauskaite, Comput. Phys. Commun. 157(2004)217.