Relativistic coupled-cluster study of SrF for low-energy precision tests of fundamental physics

Permanent electric dipole moment of diatomic molecules using relativistic extended-coupled-cluster method

“…Unitary coupled-cluster (UCC), expectationvalue coupled-cluster (XCC) and extended-coupled-cluster (ECC) approaches are three major variational forms of the CC theory found in literature. In recent times, a number of coupled-cluster-based methods have been extended to relativistic framework and these relativistic ab initio methods were used to compute energy and energy-derivatives of many-electron systems [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Molecular-frame electric dipole moment, also known as the permanent electric dipole moment (PDM), is an important first-order static property.…”

“…In recent times, a number of studies have been reported on the computation of PDMs of these molecules using various electronic structure methods [25][26][27][28]. Relativistic coupled-cluster-based methods were also employed to accurately predict the PDMs of diatomic molecules and the effects of electron-correlation and relativistic motion of electrons in computing molecular PDMs were explored [13][14][15][16][17][18]. We, in this article, employ a variational many-body method− the relativistic extended-coupled-cluster method within singles and doubles approximation to compute the PDMs of a few moderately heavy alkaline-earth metal halides and hydrides.…”