Sticking Lifetime of Ultracold CaF Molecules in Triplet Interactions

A six-dimensional potential energy surface is constructed for the spin-polarized triplet state of CaF-CaF by ab initio calculations at the CCSD(T) level of theory, followed by Gaussian process interpolation. The potential is utilized to calculate the density of states for this bialkaline-earth-halogen system where we find the value 0.038 μK^-1, implying a mean resonance spacing of 26 μK in the collision complex. This value implies an associated Rice-Ramsperger-Kassel-Marcus lifetime of 1.8 μs, thus predicting long-lived complexes in collisions at ultracold temperatures.