Ab initio Yb$_2$ ground state potential revisited
Abstract
The groundstate interaction potential of ytterbium dimer is investigated at eXact 2component corecorrelated CCSD(T) level of {\it ab initio} theory in the complete basis set limit with extensive augmentation by diffuse functions. For the basis set of double$\zeta$ quality, the comparison is made with the fourcomponent relativistic finitenuclei CCSD(T) calculations to identify the contraction of the dimer bond length as the main unrecoverable deficiency of the scalarrelativistic approximation. Empirical constraint on the number of bound vibrational energy levels of the $^{174}$Yb$_2$ dimer is accounted for by employing the model semianalytical potential function [M. Borkowski et al. Phys. Rev. A {\bf 96}, 063405 (2017)] containing the scale and shift parameters. Using the best {\it ab initio} data as its shortrange part, we estimated the equilibrium parameters of Yb$_2$ dimer as $R_e \in [4.45, 4.55]$ Å and $D_e = 745 \pm 10$ cm$^{1}$. Furthermore, we demonstrated that the model potential provides an accurate and flexible reference for future research in constraining shortrange gravitylike forces by ultracold atomic spectroscopy.
 Publication:

arXiv eprints
 Pub Date:
 July 2021
 arXiv:
 arXiv:2107.10353
 Bibcode:
 2021arXiv210710353V
 Keywords:

 Physics  Atomic Physics;
 Physics  Chemical Physics;
 Physics  Computational Physics;
 Quantum Physics
 EPrint:
 2 figures, 16 pages