Ab initio geometry optimization for large molecules

by Eckert, F.; Pulay, P.; Werner, H. J.

Various geometry optimization techniques are systematically investigated. The rational function (RF) and direct inversion in the iterative subspace (DIIS) methods are compared and optimized for the purpose of geometry optimization. Various step restriction and line search procedures are tested. The model Hessian recently proposed by Lindh et al. has been used in conjunction with different Hessian update procedures. Optimization for over 30 molecules have been performed in Z-matrix coordinates, local normal coordinates, and curvilinear natural internal coordinates, using the same approximations for the Hessian in all cases. The most effective and stable procedure for optimization of equilibrium structures was found to be the DIIS minimization in natural internal coordinates using the BFGS update of the model Hessian. Our method shows faster overall convergence than all previously published methods for the same test suite of molecules.

Journal
Journal of Computational Chemistry
Volume
18
Issue
12
Year
1997
Start Page
1473-1483
URL
https://dx.doi.org/10.1002/(sici)1096-987x(199709)18:12<1473::aid-jcc5>3.0.co;2-g
ISBN/ISSN
1096-987X; 0192-8651
DOI
10.1002/(sici)1096-987x(199709)18:12<1473::aid-jcc5>3.0.co;2-g