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Controlling errors in self-consistent field electronic structure calculations

**Emanuel Rubensson and Elias Rudberg
**

Division of Scientific Computing

Department of Information Technology

Uppsala University

### Abstract:

We present the basic components of a linear scaling self-consistent field quantum chemistry program implementing the Hartree-Fock and Kohn-Sham density functional theory methods, with particular emphasis on error control. A number of different computational approximations are applied in such programs, usually having different threshold values controlling the accuracy and computational cost of each part of the calculation. We describe a way of relating all these different threshold values to the accuracy in the fundamental quantity of interest, the electronic density. This remedies several problems that otherwise result from the many ad-hoc chosen threshold values in this kind of programs.

Reference:
Rotations of occupied invariant subspaces in self-consistent field calculations,
Emanuel H. Rubensson, Elias Rudberg, and Pawel Salek,
J. Math. Phys. 49, 032103 (2008); doi:10.1063/1.2884588, paper