Bound-State Relativistic Quantum Electrodynamics: A Perspective for Precision Physics with Atoms and Molecules

Abstract

Precision physics aims to use atoms and molecules to test and develop the fundamental theory of matter, possibly beyond the Standard Model. Most of the atomic and molecular phenomena are described by the quantum electrodynamics (QED) sector of the Standard Model. Do we have the computational tools, algorithms, and practical equations for the most possible complete computation of atoms and molecules within the QED sector? What is the fundamental equation to start with? Is it still Schrödinger’s wave equation for molecular matter, or is there anything beyond that? This paper provides a concise overview of the relativistic QED framework and recent numerical developments targeting precision physics and spectroscopy applications with common features of the robust and successful relativistic quantum chemistry methodology.

Relativistic Effects in Ligand Field Theory (I): Optical Properties of d1 Atoms in Oh′ Symmetry

“…We note that the developed theory, when combined with relativistic calculations, is suited for studying relativistic effects , in ligand field states at any order. That is, it opens up the opportunity to study the relevance of spin–spin and spin-other-orbit interactions, the nuclear charge distribution function, , or even the forthcoming quantum electrodynamics corrections to atomic and molecular states. − All of these can be explored through the p / q ratio as described in eqs and . This work contributes to the development of the ab initio ,− and density functional − ligand field theories, as well as to the determination of the spin–orbit coupling constant and the ligand field parameter for d 1 ( O h )/d 9 ( T d ) complexes from their optical spectrum without invoking the strong field approximation.…”