\textit{Ab initio} potential curves for the ground states of Ca$_{2}^+$: Existence of a double minimum in the A$^2 \Sigma_{g}^+$ state

ORAL

Abstract

We report \textit{ab initio} calculations of the X $^2 \Sigma_{u}^+ $ and A $^2 \Sigma_{g}^+$ states of the Ca$_{2}^+$ dimer. Valence multireference configuration interaction (MRCI) calculations were performed using complete active space self consistent field (CASSCF) orbitals. The CASSCF calculations included all configurations with 3 electrons in 18 valence orbitals and used the aug-cc-pV5Z basis. Core-valence and scalar relativistic effects are included at the CCSDT/cc-pWCVTZ-DK level of theory. A double well, similar to that obtained in recent calculations\footnote{S. Banerjee \textit{et al.} Chem. Phys. Lett. 496 (2010) 208.} on Be$_2^+$ is found in the A $^2 \Sigma_{g}^+$ state. Spectroscopic constants and bound vibrational levels for both the ground states are calculated, as well as Frank-Condon factors and electronic dipole transition moment between the X $^2 \Sigma_{u}^+ $ and A $^2 \Sigma_{g}^+$ states. The static dipole and quadrupole polarizabilities, along with $C_{6}$ dispersion coefficient are also reported.

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Authors

  • Jason Byrd

    University of Connecticut Department of Physics, Dept. of Physics, University of Connecticut

  • Sandipan Banerjee

    Dept. of Physics, University of Connecticut

  • Robin C\^ot\'e

    University of Connecticut, University of Connecticut Department of Physics, Dept. of Physics, University of Connecticut

  • H Michels

    Dept. of Physics, University of Connecticut

  • John Montgomery, Jr.

    University of Connecticut Department of Physics, Dept. of Physics, University of Connecticut