Full Citation: P. Pulay, "Convergence acceleration of iterative sequences. the case of scf iteration", Chem. Phys. Lett. 73, 393-398 (1980). DOI: 10.1016/0009-2614(80)80396-4.

Discussed on February 27, 2019

Description

This article describes "direct inversion" in the iterative subspace (DIIS) method, an improvement in the general self-consistent field iterative method. The simple relaxation iterative methods and their limitations are discussed, as well as the steps of the DIIS method, followed by examples. It is shown why the convergence properties of a combined method of iterative and direct approaches are much superior to those of the original iterative method, especially in SCF iteration and gradient geometry optimization. DIIS behaves much like the least squares method. Pulay was born in Hungary and fled to the United States after the Soviet invasion. Originally trained in organic chemistry, Pulay transitioned to theory and created PQS--a quantum chemistry computing software.

Keywords

Direct Inversion of the Iterative Subspace; DIIS; SCF; Lagrangian; Least Squares; error vector; Convergence