Systematic study of relativistic and chemical enhancements of P,T -odd effects in polar diatomic radicals

Abstract

Polar diatomic molecules that have, or are expected to have a 2 Σ 1/2 -ground state are studied systematically with respect to simultaneous violation of parity P and time-reversal T with numerical methods and analytical models. Enhancements of P, T -violating effects due to an electric dipole moment of the electron (eEDM) and P, T -odd scalar-pseudoscalar nucleon-electron current interactions are analyzed by comparing trends within columns and rows of the periodic table of the elements. For this purpose electronic structure parameters are calculated numerically within a quasi-relativistic zeroth order regular approximation (ZORA) approach in the framework of complex generalized Hartree-Fock (cGHF) or Kohn-Sham (cGKS). Scaling relations known from analytic relativistic atomic structure theory are compared to these numerical results. Based on this analysis, problems of commonly used relativistic enhancement factors are discussed. Furthermore the ratio between both P, T -odd electronic structure parameters mentioned above is analyzed for various groups of the periodic table. From this analysis an analytic measure for the disentanglement of the two P, T -odd electronic structure parameters with multiple experiments in dependence of electronic structure enhancement factors is derived. arXiv:1805.05494v2 [physics.chem-ph]

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

“…The reasonable agreement between cGHF/cGKS-ZORA and four component coupled cluster calculations 36,37 for W d and W s was discussed elsewhere. 19,20,36 Our present values for W d and W s differ in the last reported digit from the results in Refs. 19 and 20 as we consider herein a different isotope of Ra.…”

“…36). As observed in previous studies, 19,20 DFT tends to give results too low in absolute value. However, the value of W S still agrees reasonably (deviation is 12 %) with the coupled cluster calculations.…”

“…In comparison to relativistic coupled cluster (CC) calculations this functional performed well for the description of P, T -odd effects in diatomic radicals in our previous work, which motivates the present choice. [19][20][21] For all calculations a basis set of 37 s, 34 p, 14 d and 9 f uncontracted Gaussian functions with the exponential coefficients α i composed as an even-tempered series by α i = a · b N −i ; i = 1, . .…”

Role of electron correlation in the P,T -odd effects of CdH: A relativistic coupled-cluster investigation

“…One can see the detailed discussion on the scaling of the P, T -odd effects with Z given in Ref. [26]. We see from Table VI that the correlation contributions to E eff , W s and W M in ZnH are around 20%, 23% and 22%, respectively.…”

“…Thus, CdH can also be expected as a possible candidate for the non-spectroscopic solid-state experiment and hence, theoretical study of CdH in search of the P, Todd effects could be important. Recently, Berger and co-workers [26] performed a systematic study of the relativistic and chemical enhancements of the P, T -odd properties in various diatomic radicals including ZnH, CdH, and HgH using a quasirelativistic approach within the framework of complex generalized Hartree-Fock (cGHF) or Kohn-Sham (cGKS). In that work, the periodic trend of the P, T -odd effects was discussed in detail.…”