Computing the atomic rearrangement pathways for pure electron nuclides capture by a five-shell model. G. Galiano.

PROGRAM SUMMARY
Title of program: PATHS5
Catalogue identifier: ADKB
Ref. in CPC: 117(1999)273
Operating system: MS-DOS 3.30 and higher
High speed store required: 45K words
Number of bits in a word: 32
Number of lines in distributed program, including test data, etc: 1178
Programming language used: Fortran
Computer: IBM with 80386

Nature of physical problem:
The computation of the liquid scintillation counting efficiency for electron capture nuclides requires the determination of the atomic pathways that follows the capture of one electron by the nucleus (see [1]). A KLM three-shell model involves only 22 pathways which can be easily computed by hand. However, the complexity of determining the rearrangement pathways highly increases when more shells are considered in the model. We propose an algorithm to compute these pathways for a five-shell model which can be extended to more complex situations.

Method of solution
We consider a tree of five levels where three annihilation-creation of vacants operators are defined. We run over all the different possibilities of action of these operators, obtaining in this way all the rearrangement pathways.

Restriction on the complexity of the problem
We average M subshells. We do not consider the atomic rearrangement for M and outer shells.

Typical running time
0.7 sec of cpu time on a Pentium 122Mh, 16Mb, IBM-compatible computer.

References

 [1] A. Grau Malonda, Appl. Rad. Isotop. 33 (1982) 371.