Comparative study of the \textit{ab initio} potential curves for Be$_2^+$, Mg$_2^+$, Ca$_2^+$ and Sr$_2^+$ molecular ions

ORAL

Abstract

We perform a comparative study of the X~$^2 \Sigma_{u}^+$, A~$^2\Pi_u$ and B~$^2 \Sigma_{g}^+$ states in the homonuclear alkaline-earth family of molecular ions --- Be$_2^+$, Mg$_2^+$, Ca$_2^+$ and Sr$_2^+$. A qualitative comparison of the ``double-well" in the B~$^2 \Sigma_{g}^+$ state and interaction with the excited 2~$^2 \Sigma_{g}^+$ state is made for all the molecular ions. Multireference configuration interaction (MRCI) calculations are performed with a complete active space (CAS) wavefunction as reference. Spectroscopic constants, bound vibrational levels, transition moments and radiative lifetimes are calculated. The static dipole and quadrupole polarizabilities, and the leading order van der Waals coefficients are also reported. We also show preliminary results for corrections to the Born-Oppenheimer Hamiltonian --- non-adiabatic couplings and and hyperfine structure due to nuclear spins and electric quadrupoles.

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Authors

  • Sandipan Banerjee

    University of Connecticut, Dept. of Physics, University of Connecticut, Storrs, CT 06269

  • John Montgomery

    Dept. of Physics, University of Connecticut, Storrs, CT 06269

  • Robin Cote

    Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA, University of Connecticut, Dept. of Physics, University of Connecticut, Storrs, CT 06269, University of Connecticut Department of Physics