A program of generation and selection of configurations for the configuration interaction method in atomic calculations SELECTCONF

Abstract

This program written in FORTRAN is aimed at generation and selection of the admixed configurations which are used in the theoretical calculations of atomic states by the configuration interaction (CI) method. The admixed configurations are generated and selected using the file of radial orbitals written down in the form adopted in the code [C. Froese Fischer, Comput. Phys. Comm. 43 (1987) 355] and other analogous codes. Selection of configurations is performed on the ground of evaluations in the second order of the perturbation theory [P. Bogdanovich, R. Karpuškienė, Comput. Phys. Comm. 134 (2001) 321; R. Karpuškienė, R. Karazija, P. Bogdanovich, Phys. Scripta 64 (2001) 333]. Output of selected configurations is arranged in a format suitable for the codes generating the configuration states [C. Froese Fischer, B. Liu, Comput. Phys. Comm. 64 (1991) 406; P. Bogdanovich, A. Momkauskaitė, Comput. Phys. Comm. 157 (2004) 217]. Program summary Title of program:SELECTCONF Catalogue identifier:ADWD Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADWD Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Licensing provisions:None Computers:Any computer with a FORTRAN 77 compiler Operating systems under which the program has been tested:Linux Programming language used:FORTRAN 77 Memory required to execute with typical data:4 MB No. of lines in distributed program, including test data, etc.:7459 No. of bytes in distributed program, including test data, etc.:108 420 Distribution format:gzip file Nature of the physical problem:Due to the restricted possibilities of the computers and codes, which are employed, the practice of CI requires one to select and superpose those configurations the usage of which happens to be the most effective. This program is designed for the selection of such admixed configurations. Method of solution: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 onto the complexity of the problem: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 of the program: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. Typical 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.