Figure 1: K–KRb potential energy surface.
From: Universality and chaoticity in ultracold K+KRb chemical reactions

(a) A two-dimensional cut through the energetically lowest 2A′ (blue curve) and 2B′ (red curve) adiabatic potential energy surfaces of the KRbK trimer as a function of the K−Rb bond lengths and the angle between K−Rb−K along the isosceles C2ν geometry with RK1Rb=RK2Rb. The base of the figure shows the corresponding contour graph. The zero of energy corresponds to the energy of three well-separated atoms. The unit of length is the Bohr radius a0=0.0529177, nm and that of energy is wavenumbers. (b) A contour graph of the K−Rb−K potentials based on the data in a. Contour labels are in units of 103 cm−1. In both panels the seam of conical intersections is shown by the green line.