ИСТИНА

Reliable estimates of the energies, magnetic and electric properties of the ground and low-lying excited diatomic states are crucial to design optimal optical cycle for producing ultracold molecules in their absolute ground state (v=J=0). We report here ab initio relativistic calculations on potential energy curves and electric properties (static dipole polarizabilities and permanent dipole moments) of the RbCs electronic states dissociating to the ground (5s ^2S_{1/2} (Rb) + 6s ^2S_{1/2} (Cs)) and excited (5s ^2S_{1/2} (Rb) + 6p ^2P_{1/2; 3/2} (Cs)) atomic states. The assumed relativistic electronic structure model is defined by the two-component small-core shape-consistent pseudopotentials (PPs) replacing the inner electron shells of each atom [1]. These pseudopotentials were optimized for the accurate description of the ground and low-lying excited atomic states, emerging from the excitations of the valence s-electron of the alkali (Rb, Cs) atom. Valence and subvalence ((n − 1)s(n − 1)p) electrons were correlated explicitly. Correlation calculations were performed using the two-component spinors as one-electron basis set. The components of the spinors were expanded in the basis of Gaussian functions. Static polarizabilities and permanent dipole moments of the ground and excited states under study were calculated by finite-field method. The deviations of computed energies and static dipole polarizabilities at the dissociation limits from the relevant atomic values do not exceed 0.8% and 3.5%, respectively. The obtained data will be utilized to estimate the energies and electric properties of the fully mixed levels of the RbCs molecule located near the second dissociation limit [2], [3]. The calculations were performed with the DIRAC12 package. The present work was supported by the RFBR under Grant No. 13-03-00466. [1] N. S. Mosyagin, A. Zaitsevskii, A. V. Titov, Int. Rev. At. Mol. Phys. 1, 63–72 (2010). [2] doi: 10.1103/PhysRevLett.92.153001, A. J. Kerman, J. M. Sage, S. Sainis, T. Bergeman, D. DeMille, Phys.Rev.Lett. 92, 033004-4 (2004). [3] doi: 10.1063/1.4901327, A. Kruzins, K. Alps, O. Docenko, I. Klincare, M. Tamanis, R. Ferber, E. A. Pazyuk and A. V. Stolyarov, J. Chem. Phys. 141, 184309 (2014).