Novel adaptive grid for electronic structure calculations

COMP 99

Juan I. Rodríguez, rodrigji@mcmaster.ca1, David C. Thompson, dthompson@wyeth.com2, and Paul W. Ayers, ayers@mcmaster.ca1. (1) Department of Chemistry, McMaster University, Hamilton, ON L8S4M1, Canada, (2) Department of Structural Biology & Computational Chemistry, Wyeth Research, Chemical & Screening Sciences, 200 Cambridge Park Drive, Cambridge, MA 02140
Although integration grids are often used in electronic structure programs, they are usually only applied to the pieces of a calculation where analytical integration is impossible or impractical (e.g., the integration of the exchange-correlation energy functional in Kohn-Sham density-functional theory). It is also possible, however, to integrate the entire energy functional using grids, but for this more demanding application it is important to have effective grids. (The effectiveness of a grid is related to the number of grid points required to achieve a given accuracy.) In this work we will introduce a novel adaptive grid suitable to be used in electronic structure calculations. This grid is adaptive and flexible enough to be used to integrate the exchange-correlation, coulomb and the whole energy. We will show some examples of the use of this grid like in solving the Poisson equation. Finally we will discuss the “effectiveness” of our grid.