Authors: L.F. McAven, M. Schlesinger and R.D. Kent
Affilation: University of Windsor, Canada
Pages: 181 - 184
Keywords: distributed processing, group theory, matrix elements, recursion, Racah-Wigner calculus
Interaction stregths and material properties are represented mathematically by matrix elements. The calculation of matrix elements is therefore critical in the interpretation and modelling of physical systems. Part of the matrix elements can be factored out as symmetry coefficeints of the Racah-Wigner Calculus. One powerful, and widely applicable approach to calculating those coefficients, is a recursive technique which expresses higher power coefficients in terms of lower power ones. A recent recursive algorithm is implemented in RACAH, a package for calculating matrix elements of arbitrary Hamiltonians. We discuss issues involving the use of this algorightm in a distributed environment. A major part of distributed efficiency lies in the management of factorisation, simplification and the recursion, and we concentrate on these aspects. Coefficients frequently reappear in recursion and one needs to balance independence against exact non-reproductions.