Geometry optimizations in the zero order regular approximation for relativistic effects

Density functional calculations of molecular g-tensors in the zero-order regular approximation for relativistic effects

The zero-order regular approximation for relativistic effects: The effect of spin–orbit coupling in closed shell molecules

In this paper we will calculate the effect of spin–orbit coupling on properties of closed shell molecules, using the zero-order regular approximation to the Dirac equation. Results are obtained using density functionals including density gradient corrections. Close agreement with experiment is obtained for the calculated molecular properties of a number of heavy element diatomic molecules. © 19...

Density functional calculations of nuclear quadrupole coupling constants in the zero-order regular approximation for relativistic effects

The zeroth-order regular approximation ~ZORA! is used for the evaluation of the electric field gradient, and hence nuclear quadrupole coupling constants, in some closed shell molecules. It is shown that for valence orbitals the ZORA-4 electron density, which includes a small component density ~‘‘picture-change correction’’!, very accurately agrees with the Dirac electron density. For hydrogen-l...

Relativistic nuclear magnetic resonance J-coupling with ultrasoft pseudopotentials and the zeroth-order regular approximation.

We present a method for the first-principles calculation of nuclear magnetic resonance (NMR) J-coupling in extended systems using state-of-the-art ultrasoft pseudopotentials and including scalar-relativistic effects. The use of ultrasoft pseudopotentials is allowed by extending the projector augmented wave (PAW) method of Joyce et al. [J. Chem. Phys. 127, 204107 (2007)]. We benchmark it against...

A gauge-independent zeroth-order regular approximation to the exact relativistic Hamiltonian--formulation and applications.

A simple modification of the zeroth-order regular approximation (ZORA) in relativistic theory is suggested to suppress its erroneous gauge dependence to a high level of approximation. The method, coined gauge-independent ZORA (ZORA-GI), can be easily installed in any existing nonrelativistic quantum chemical package by programming simple one-electron matrix elements for the quasirelativistic Ha...