Gerardo Lara Cisneros

Improved solutions to the one-center McMurchie-Davidson tree search problem

We present an improvement to Johnson, Gill, and Poples results for reducing the cost of using the McMurchie–Davidson RNLM recurrence relation for one‐center integrals. Recursive replacement of singly referenced and single‐term auxiliary integrals results in floating point operation (FLOP) savings of up to 11% and explicit auxiliary integral calculation reductions of up to 76% with respect to the full list and up to 46% with respect to FLOP‐reduced lists with no replacement. The programs are written in the string‐manipulation language Convert; one of the programs automatically generates a FORTRAN subroutine given an integral list.

Configurable REC

This paper describes CREC, a library of C functions for compiling and executing REC programs whose operators and predicates are provided by the caller. Given a C program with a menu-based interactive interface, REC can be added as a programming language to the user interface by assigning menu choices to REC operators and predicates through entries in a table, and linking in the appropriate functions in CREC. Being a very concise language, REC programs are easy to write in an interactive context. The same conciseness allows the compiler to require only a small amount of space. Experience whereby the library benefitted some mathematics and physics programs is described.