Stochastic hyperfine interactions modeling library—Version 2

The stochastic hyperfine interactions modeling library (SHIML) provides a set of routines to assist in the development and application of stochastic models of hyperfine interactions. The library provides routines written in the C programming language that (1) read a text description of a model for fluctuating hyperfine fields, (2) set up the Blume matrix, upon which the evolution operator of the system depends, and (3) find the eigenvalues and eigenvectors of the Blume matrix so that theoretical spectra of experimental techniques that measure hyperfine interactions can be calculated. The optimized vector and matrix operations of the BLAS and LAPACK libraries are utilized. The original version of SHIML constructed and solved Blume matrices for methods that measure hyperfine interactions of nuclear probes in a single spin state. Version 2 provides additional support for methods that measure interactions on two different spin states such as Mössbauer spectroscopy and nuclear resonant scattering of synchrotron radiation. Example codes are provided to illustrate the use of SHIML to (1) generate perturbed angular correlation spectra for the special case of polycrystalline samples when anisotropy terms of higher order than A22 can be neglected and (2) generate Mössbauer spectra for polycrystalline samples for pure dipole or pure quadrupole transitions. Program title: SHIML Catalogue identifier: AEIF_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIF_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 3 with supplemental citation provision No. of lines in distributed program, including test data, etc.: 88510 No. of bytes in distributed program, including test data, etc.: 3311047 Distribution format: tar.gz Programming language: C. Computer: Any. Operating system: LINUX, OS X. RAM: Variable Catalogue identifier of previous version: AEIF_v1_0 Journal reference of previous version: Comput. Phys. Comm. 182(2011)1061 Classification: 7.4. External routines: TAPP [1], BLAS [2], a C-interface to BLAS [3], and LAPACK [4]. Additionally, GSL [3] is needed to compile the example code that simulates Mössbauer spectra. Does the new version supersede the previous version?: No Nature of problem: In condensed matter systems, hyperfine methods such as nuclear magnetic resonance (NMR), Mössbauer effect (ME), muon spin rotation (μSR), and perturbed angular correlation spe