The ground-state potential energy curve of the radium dimer from relativistic coupled cluster calculations

Tiago Quevedo Teodoro; Roberto Luiz Andrade Haiduke; Umakanth Dammalapati; Steven Knoop; Lucas Visscher

doi:10.1063/1.4929348

The ground-state potential energy curve of the radium dimer from relativistic coupled cluster calculations

J Chem Phys. 2015 Aug 28;143(8):084307. doi: 10.1063/1.4929348.

Authors

Tiago Quevedo Teodoro¹, Roberto Luiz Andrade Haiduke², Umakanth Dammalapati³, Steven Knoop⁴, Lucas Visscher¹

Affiliations

¹ Amsterdam Center for Multiscale Modeling, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
² Department of Chemistry and Molecular Physics, São Carlos Institute of Chemistry, University of São Paulo, Trabalhador São-Carlense Avenue, 400-CP 780, 13560-970 São Carlos, SP, Brazil.
³ Department of Physics, The University of Dodoma, P.O. Box 338, Dodoma, Tanzania.
⁴ LaserLab, Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.

PMID: 26328843
DOI: 10.1063/1.4929348

Abstract

The potential energy curve for the ground-state of radium dimer (Ra2) is provided by means of atomic and molecular relativistic coupled cluster calculations. The short-range part of this curve is defined by an equilibrium bond length of 5.324 Å, a dissociation energy of 897 cm(-1), and a harmonic vibrational frequency of 20.5 cm(-1). The asymptotic behavior at large interatomic distances is characterized by the van der Waals coefficients C6 = 5.090 × 10(3), C8 = 6.978 × 10(5), and C10 = 8.786 × 10(7) atomic units. The two regions are matched in an analytical potential to provide a convenient representation for use in further calculations, for instance, to model cold collisions between radium atoms. This might become relevant in future experiments on ultracold, optically trapped, radioactive radium atoms that are used to search for a permanent electric dipole moment.