Approximate relativistic coupled-cluster calculations on heavy alkali-metal diatomics: Application to the spin-orbit-coupled A(1)Sigma(+) and b(3)Pi states of RbCs and Cs-2

作者：Zaitsevskii A^*; Mosyagin N S; Stolyarov A V; Eliav E^*

来源：PHYSICAL REVIEW A, 2017, 96(2): 022516.

DOI：10.1103/PhysRevA.96.022516

A simple approximate version of the Fock-space relativistic coupled-cluster method is developed and applied for modeling the spin-orbit-coupling effect in the A(1)Sigma(+)((u)) and b(3)Pi((u)) states of the heavy alkali diatomics RbCs and Cs-2. Numerical stability in a wide range of molecular geometries is achieved at the cost of a very moderate loss of accuracy for low-lying states and negligibly small deviations of the computational scheme from strict size consistency. The adiabatic potential energy curves computed for the (2,3)0(+) (RbCs) and (1,2)0(u)(+) (Cs-2) states are converted into "quasidiabatic" potentials and effective spin-orbit-coupling functions via projection of the scalar relativistic states onto the subsets of fully relativistic states. A detailed comparison of the present ab initio results with their experimental and preceding theoretical counterparts is performed.

• 出版日期2017-8-29