Elsevier Science Home
Computer Physics Communications Program Library
Full text online from Science Direct
Programs in Physics & Physical Chemistry
CPC Home

[Licence| Download | New Version Template] abjm_v1_0.gz(14 Kbytes)
Manuscript Title: Perturbation functions: PAC probe nuclei, I=2, 5/2, and 3.
Authors: G.L. Catchen
Program title: ACOEFF
Catalogue identifier: ABJM_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 55(1989)85
Programming language: Fortran.
Computer: IBM 3090-400E.
Operating system: OS/VS2.
RAM: 2217K words
Word size: 32
Keywords: Nuclear physics, Spectroscopy, Perturbation function, Attenuation coefficient, Perturbed angular Correlation, Level scheme.
Classification: 17.15.

Nature of problem:
In Perturbed Angular Correlation (PAC) Spectroscopy, static nuclear- electric-quadrupole interactions are described by perturbation functions (attenuation coefficients). For a quadrupole interaction with a non- axially-symmetric electric field gradient, the perturbation function calculation involves a summation over projection quantum numbers, Wigner 3-j coefficients, and the associated unitary matrix elements.

Solution method:
The calculation can be performed for spins, I=2, 5/2, and 3, for the case of a polycrystalline source of PAC probe nuclei. The Wigner 3-j coefficients that correspond to all of the m-to-m' transitions are generated and stored as a matrix. For each value of the assymetry parameter, eta, the program generates the unitary matrix and performs the summation. The program calculates and prints the associated m- state energy differences, a-coefficients, and perturbation functions, Gkk(t) for k=2 and 4 (I=2 and 5/2) and k=2, 4, and 6 (I=3).

Restrictions:
Only sources of probe nuclei in randomly-oriented crystals, i.e., polycrystalline sources, are considered. The perturbation functions are calculated in 101 steps of (Omega0 *t/2*n*pi) in which n is usually chosen to be 1 or 2.

Unusual features:
The program contains all of the Wigner 3-j coefficients needed for the calculation. From the corresponding closed-forms expressions, the program generates the m-state energy differences and the eigenvectors that compose the unitary transformation.

Running time:
14s (4s, VS compiler) (for I=3, perturbation functions are calculated for 11 values of eta) and 40s (9s, VS compiler) (for I=5/2, S- coefficients are calculated for 101 values of eta and no perturbation functions are calculated).