Calculation of reduced coefficients and matrix elements in jj–coupling

A program RCFP will be presented for calculating standard quantities in the decomposition of many–electron matrix elements in atomic structure theory. The list of quantities wich are supported by the present program includes the coefficients of fractional parentage, the reduced coefficients of fractional parentage, the reduced matrix elements of the unit operator T (k) as well as the completely reduced matrix elements of the operator W (kjkq) in jj–coupling. These quantities are now available for all subshells (nj) with j ≤ 9/2 including partially filled 9/2–shells. Our program is based on a recently developed new approach on the spin–angular integration which combines second quantization and quasispin methods with the theory of angular momentum in order to obtain a more efficient evaluation of many–electron matrix elements. An underlying Fortran 90/95 module can directly be used also in (other) atomic structure codes to accelerate the computation for open–shell atoms and ions. PROGRAM SUMMARY Title of program: RCFP Catalogue number: ADNA Program obtainable from: CPC Program Library, Queen’s University of Belfast, N. Ireland. Users may obtain the program also by down–loading a tar–file ratip-rcfp.tar from our home page at the University of Kassel (http://www.physik.uni-kassel.de/fritzsche/programs.html). Licensing provisions: None. Computer for which the program is designed and has been tested: IBM RS 6000, PC Pentium II. Installations: University of Kassel (Germany). Operating systems: IBM AIX 4.1.2+, Linux 6.1+. Program language used in the new version: ANSI standard Fortran 90/95. Memory required to execute with typical data: 100 kB. No. of bits in a word: All real variables are parametrized by a selected kind parameter and, thus, can be adapted to any required precision if supported by the compiler. Currently, the kind parameter is set to double precision (two 32–bit words) as it is for other components of the RATIP package [1]. Peripheral used: Terminal for input/output. Distribution format: tar gzip file CPC Program Library Subprograms required: Catalogue number: to be assigned: Title: REOS99; Ref. [1]