Emanuel Rubensson
Department of Theoretical Chemistry
KTH
Stockholm
In electronic structure calculations such as Hartree-Fock or Kohn-Sham
Density Functional calculations, an important operation is the computation
of the density matrix for a given potential; the density matrix is used to
represent the electron density. The traditional approach to compute the
density matrix uses diagonalization of the potential matrix (the
Fock/Kohn-Sham matrix). The computational cost of this operation increases
cubically with system size. In recent years, methods for which the needed
computational effort increases only linearly with system size have become
popular. In this seminar I will talk about one of these methods: density
matrix purification. I will focus on how errors due to computational
approximations can be controlled.
See the article in J. Chem. Phys. 128, 074106 (2008).