Toolbox approach for quasi-relativistic calculation of molecular properties for precision tests of fundamental physics

Abstract

A generally applicable approach for the calculation of relativistic one-electron properties with two-component wave functions is presented. The formalism is explicitly evaluated for the example of quasi-relativistic wavefunctions obtained within the zeroth order regular approximation (ZORA). The wide applicability of the scheme is demonstrated for the calculation of parity (P) and time-reversal (T ) symmetry violating properties, which are important for searches of physics beyond the standard model of particle physics. The quality of the ZORA results is shown exemplarily for the molecules RaF and TlF by comparison to data from fourcomponent calculations as far as available. Finally, the applicability of RaF in experiments that search for P, T -violation not only in the electronic but also in quark sector is demonstrated.

Parity nonconserving interactions of electrons in chiral molecules with cosmic fields

“…Quasi-relativistic two-component calculations of H 2 X 2 and H 2 XO with X = O, S, Se, Te, Po and CHBrClF are performed within the zeroth order regular approximation (ZORA) at the level of complex generalized Hartree-Fock (cGHF) or Kohn-Sham (cGKS) with a modified version [54][55][56][57][58][59][60] of the quantum chemistry program package Turbomole [61].…”

Isotope Shifts of Radium Monofluoride Molecules

“…In this Letter we investigate, theoretically and experimentally, the changes in the molecular energy levels when neutrons are added to (or removed from) the radium nucleus of RaF molecules. RaF molecules are of special interest for fundamental physics research as their electronic structure is predicted to provide a large enhancement of both parity and time-reversal violating effects [4,8,[26][27][28]. Moreover, some nuclei in the very long isotope chain of Ra (Z = 88) exhibit octupole deformation [29,30], which results in a significant amplification of their symmetry-violating nuclear properties, relative to light molecules [2,3].…”

Chiral Molecules as Sensitive Probes for Direct Detection of P -Odd Cosmic Fields

“…Parity-violating molecular properties were computed on the level of two-component zeroth order regular approximation complex generalized Kohn-Sham (ZORA-CGKS) (see Refs. [54][55][56]) employing the exchange correlation functional B3LYP [57][58][59][60]. We reuse electronic densities and Kohn-Sham orbitals as well as vibrational wave functions determined in Ref.…”

“…With these, electronic expectation values of γ 5 ¼ P i γ 5 i , with index i running over all electrons in the system, and of the nuclearspin independent electroweak electron-nucleon current interaction term induced byĤ ew ¼ P iĥew ðiÞ were calculated with our ZORA property toolbox approach outlined in Ref. [56]. Vibrational corrections of the properties were computed as described in Ref.…”