Improved solutions to the one‐center McMurchie—Davidson tree search problem

We present an improvement to Johnson, Gill, and Pople's results for reducing the cost of using the McMurchie–Davidson R NLM 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.