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Manuscript Title: Computer simulations of Mossbauer spectra for an effective spin S=1/2 Hamiltonian.
Authors: E. Munck, J.L. Groves, T.A. Tumolillo, P.G. Debrunner
Program title: PARAMAGNETIC MOSSBAUER SPECTRA
Catalogue identifier: ABMD_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 5(1973)225
Programming language: Fortran.
Computer: IBM 360/75.
Operating system: HASP-OS/MVT.
RAM: 35K words
Word size: 64
Keywords: Nuclear physics, Spin 1/2 hamiltonian, Iron-57, Mossbauer spectra, Polycrystalline sample.
Classification: 17.3.

Revision history:
Type Tit le Reference
correction 000A CORRECTION 18/01/73 See below

Nature of problem:
We have written a computer program that calculates the Mossbauer spectra of iron-57 in paramagnetic polycrystalline samples in an external magnetic field using a spin hamiltonian.

Solution method:
An expression of the intensity of a Mossbauer spectrum is derived. The expression contains Clesbsch-Gordan coefficients, functions describing the absorption of radiation as a function of the angle between the observation direction and the nuclear quantization axis, a line-shape function, and coefficients which describe the nuclear eigenstates as linear combinations of the eigenstates of the nuclear spin operators. The coefficients are obtained by solving the spin hamiltonian.

Restrictions:
The external field, H, is assumed to be sufficiently large (H>=20G) to make the electronic Zeeman term much greater than any other term in the hamiltonian. The electron spin relaxation time is long compared to the nuclear precession time. The spin doublet described by the hamiltonian must be sufficiently isolated from other electronic states such that the applied field H does not mix other levels into the spin doublet. In practice this condition is fulfilled for fields less than 1kG.

Running time:
A typical CPU time for a 256 channel spectrum calculated with 18 X 18 integrations over Beta o and Gamma o is 25 s.

CORRECTION SUMMARY
Manuscript Title: Computer simulations of Mossbauer spectra for an effective spin S=1/2 Hamiltonian. (C.P.C. 5(1973)225).
Authors: E. Munck, J.L. Groves, T.A. Tumolillo, P.G. Debrunner
Program title: 000A CORRECTION 18/01/73
Catalogue identifier: ABMD_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 5(1973)395
Classification: 17.3.