Combined 4-component and relativistic pseudopotential study of ThO for the electron electric dipole moment search.
Combined 4-component and relativistic pseudopotential study of ThO for the electron electric dipole moment search.
复制标题
用于电子电偶极矩搜索的 ThO 的四分量和相对论赝势联合研究。
DOI：
10.1063/1.4968229
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
L. Skripnikov
中科院分区：
文献类型：
--
作者：
L. Skripnikov;L. Skripnikov
对重原子双原子分子电子结构的精确理论研究对于解释在电子电偶极矩、eEDM 和无量纲常数 kT,P（表征 T,P-奇数赝标量-标量电子-核中性电流相互作用的强度）方面违反基本相互作用的时间反转 (T) 和空间宇称 (P) 对称性的实验至关重要。 ACME 合作最近使用电子 H3Δ1 态的 ThO 分子束改进了对这些数量的限制 [J. Baron 等人，科学 343, 269 (2014)]。我们将直接相对论四分量和两步相对论赝势/恢复方法相结合，对 ThO 分子 Δ13 态下的有效电场 Eeff、T,P 奇赝标量-标量相互作用的参数、WT,P 和超精细结构常数进行基准计算。需要前两个参数来解释 eEDM 和 kT,P 常数的实验数据。我们已经研究了 ThO 的所有 98 个电子的电子相关性，同时达到耦合簇水平，具有单振幅、双振幅和非迭代三振幅 CCSD(T) 理论。还处理了价电子的迭代三重和非迭代四重簇振幅的贡献。获得的值为 Eeff = 79.9 GV/cm，WT,P = 113.1 kHz。这些值的理论不确定性估计比我们之前的研究[L. V. Skripnikov 和 A. V. Titov，J. Chem。物理学, 142, 024301 (2015)]。研究发现，内核和外核电子的相关性对有效电场的贡献率为9%。采用相同方法计算得到的Δ13态分子骨架偶极矩和ThO的H3Δ1→X1Σ+跃迁能值与实验结果吻合较好。
A precise theoretical study of the electronic structure of heavy atom diatomic molecules is of key importance to interpret the experiments in the search for violation of time-reversal (T) and spatial-parity (P) symmetries of fundamental interactions in terms of the electron electric dipole moment, eEDM, and dimensionless constant, kT,P, characterizing the strength of the T,P-odd pseudoscalar-scalar electron-nucleus neutral current interaction. The ACME collaboration has recently improved limits on these quantities using a beam of ThO molecules in the electronic H3Δ1 state [J. Baron et al., Science 343, 269 (2014)]. We apply the combined direct relativistic 4-component and two-step relativistic pseudopotential/restoration approaches to a benchmark calculation of the effective electric field, Eeff, parameter of the T,P-odd pseudoscalar-scalar interaction, WT,P, and hyperfine structure constant in Δ13 state of the ThO molecule. The first two parameters are required to interpret the experimental data in terms of the eEDM and kT,P constant. We have investigated the electron correlation for all of the 98 electrons of ThO simultaneously up to the level of the coupled cluster with single, double, and noniterative triple amplitudes, CCSD(T), theory. Contributions from iterative triple and noniterative quadruple cluster amplitudes for the valence electrons have been also treated. The obtained values are Eeff = 79.9 GV/cm, WT,P = 113.1 kHz. The theoretical uncertainty of these values is estimated to be about two times smaller than that of our previous study [L. V. Skripnikov and A. V. Titov, J. Chem. Phys., 142, 024301 (2015)]. It was found that the correlation of the inner- and outer-core electrons contributes 9% to the effective electric field. The values of the molecule frame dipole moment of the Δ13 state and the H3Δ1→X1Σ+ transition energy of ThO calculated within the same methods are in a very good agreement with the experiment.