Scalar-relativistic effects in solids in the framework of a Douglas-Kroll transformed Dirac-Coulomb Hamiltonian

TL;DR

This paper applies the Douglas-Kroll transformed Dirac-Coulomb Hamiltonian within a Hartree-Fock framework to efficiently study scalar-relativistic effects in crystalline solids, specifically silver compounds, using the CRYSTAL program.

Contribution

It introduces a method to incorporate scalar-relativistic effects in solids using a relativistic Hamiltonian with periodic boundary conditions, implemented in the CRYSTAL software.

Findings

Scalar-relativistic effects significantly influence formation energies and structural properties.

The method accurately predicts lattice parameters and bulk moduli for silver compounds.

Results demonstrate the importance of relativistic effects in heavy-element solids.

Abstract

The Douglas-Kroll transformed Dirac-Coulomb Hamiltonian is used to describe scalar-relativistic effects in solids. A Hartree-Fock approximation with periodic boundary conditions makes it feasible to use methods originally developed for atoms and molecules to solve the corresponding equations for crystalline systems. The implementation is realized within the CRYSTAL program. Scalar-relativistic effects in silver compounds of FCC structure such as AgF, AgCl, AgBr and Ag are investigated for the molar formation energy, the lattice parameter, the isothermal bulk modulus and the pressure derivative.