MACS J A PROGRAM FOR COMPUTING CRYSTAL PHONON DISPERSION RELATIONS, STRUCTURE FACTORS FOR NEUTRON INELASTIC SCATTERING, AND JACOBEAN MATRICES

摘要

This report describes a FORTRAN IV program MACS J (PPCo 40*0929) which computes (a) the dynamical matrix for the harmonic oscillations of a crystal, (b) the eigenvalues and eigenvectors of this matrix, (c) the corresponding structure factors for coherent single-phonon scattering of neutrons, and (d) Jacobian matrices for use in adjusting force constants to fit calculated dispersion curves to observed dispersion curves. Appendixes contain discussion of fitting procedures and the linearity assumption as well as sample input for calculation of a Jacobian matrix.nRunning time on an IBM 7044 (32K, batch processing) for the 7 problems required to calculate a Jacobian with 8 rows and 6 columns for BeO {4 atoms per primitive cell) is less than 5 minutes.