Potential energy surface and bound states of the (X⁴Σ)KRb‐K complex

Abstract

We present in this work a potential energy surface of the (X4Σ)KRb‐K complex for which high level ab initio calculations have been carried out at the RCCSD(T) level of theory, using ECP10MDF/ECP28MDF effective core potentials and basis sets for K/Rb, respectively, with the dimer at its lowest triplet 3Σ state and fixed to the equilibrium distance. The interaction is shown to be very anisotropic, with one clear minimum at a T‐type geometry of the complex. The depth of the well is found to be 767.7 cm−1 located at R=4.60 Å,θ=105° in Jacobi coordinates from the center of mass of the diatomic partner. A variational (VAR) procedure and the Diffusion Monte Carlo technique have been applied to explore the bound states of the aggregate. Both descriptions provide similar features for the vibrational, nonrotating, ground‐state, with an energy of ∼−737.8 cm−1 and the maximum of the wavefunction peaked above the well of the surface. Excited states are also reported using the VAR treatment and angular and/or radial excitations are identified among the lower‐lying vibrational states. These results should already provide an initial step toward a more comprehensive study of the collisions at ultralow temperatures of K+KRb, important process in the field of ultracold molecular chemistry. © 2014 Wiley Periodicals, Inc.

Universality and chaoticity in ultracold K+KRb chemical reactions

“…The first theoretical studies of the electronic structure of three-and four-body alkali-metal systems focused on homonuclear trimers [33][34][35]. Initial studies of heteronuclear alkali-metal trimer and tetramer potentials principally located optimized geometries and dissociation energies [36][37][38].…”