Quantum chemistry with the Douglas-Kroll-Hess approach to relativistic density functional theory: Efficient methods for molecules and materials

Perspective: Relativistic effects

“…Another quasi-relativistic Hamiltonian that has found wide-spread use 109,110 is the Douglas-Kroll-Hess (DKH) Hamiltonian which is constructed via a sequence of transformations U = U 0 U 1 U 2 ··· in orders of the potential V. For a free particle, the FW transformation to block-diagonal form can be written in closed form. When the free-particle FW transformation is applied to the Dirac Hamiltonian with an external potential, one obtains 26…”

Density Functional Embedded Cluster Study of Cu4, Ag4 and Au4 Species Interacting with Oxygen Vacancies on the MgO(001) Surface

“…In calculations involving 4d (Ag) and 5d atoms (Au), we used a scalar relativistic variant based on a second-order Douglas-Kroll transformation to decouple electronic and positronic degrees of freedom of the Dirac-Kohn-Sham equation. [21,22] The Gaussian-type atomic orbital basis sets, contracted in generalized fashion, were the same as in our previous studies: [12][13][14][15] …”

Looking back at dense linear algebra software

“…For example, early versions of ParaGauss [10,11,12,13] relied on diagonalization of the Kohn-Sham matrix and the parallelization method of choice relied on the irreducible representations of the point group. The submatrices diagonalize in parallel and the number of them depended on the symmetry group.…”