Tackling component interoperability in quantum chemistry software

The Common Component Architecture (CCA) offers an environment that allows scientific packages to dynamically interact with each other through components. Conceptually, a computation can be constructed with plug-and-play components from any componentized scientific package; however, providing such plug-and-play components from scientific packages requires more than componentizing functions/subroutines of interest, especially for large-scale scientific packages with a long development history. In this paper, we present our efforts to construct components for the integral evaluation - a fundamental sub-problem of quantum chemistry computations - that conform to the CCA specification. The goal is to enable fine-grained interoperability between three quantum chemistry packages, GAMESS, NWChem, and MPQC, via CCA integral components. The structures of these packages are quite different and require different approaches to construct and exploit CCA components. We focus on one of the three packages, GAMESS, delineating the structure of the integral computation in GAMESS, followed by our approaches to its component development. Then we use GAMESS as the driver to interoperate with integral components from another package, MPQC, and discuss the possible solutions for interoperability problems along with preliminary results.