Calculations of Time-Reversal Symmetry Violation Sensitivity Parameters Based on Analytic Relativistic Coupled-Cluster Gradient Theory

TL;DR

This paper introduces an improved analytic-gradient relativistic coupled-cluster method to accurately compute electric field sensitivity parameters crucial for electron EDM experiments, enabling better candidate screening.

Contribution

The authors develop a more efficient and robust analytic-gradient approach for relativistic coupled-cluster calculations of $ ext{E}_{ ext{eff}}$, advancing the computational tools for eEDM research.

Findings

Metal methoxides have large $ ext{E}_{ ext{eff}}$ values comparable to fluorides and hydroxides.

Certain actinide-containing molecules exhibit exceptionally high $ ext{E}_{ ext{eff}}$ around 200 GV/cm.

The method facilitates screening of molecules for electron EDM experiments.

Abstract

We develop an analytic-gradient based method for relativistic coupled-cluster calculations of effective electric field, $\mathcal{E}_{\text{eff}}$, with improved efficiency and robustness over the previous state of the art. The enhanced capability to calculate this time-reversal symmetry violation sensitivity parameter enables efficient screening of candidate molecules for the electron electric dipole moment (eEDM) search. As examples, the |$\mathcal{E}_{\text{eff}}$| values of metal methoxides including BaOCH$_3$, YbOCH$_3$, and RaOCH$_3$ are shown to be as large as those of the corresponding fluorides and hydroxides, which supports the recent proposal of using these symmetric-top molecules to improve the sensitivity of eEDM measurements. The computational results also show that molecules containing late actinide elements, NoF, NoOH, LrO, and LrOH$^+$, exhibit particularly large |$\mathcal{E}_{\text{eff}}$| values of around 200 GV/cm.