A Global Full-Dimensional Potential Energy Surface for the K₂Rb₂ Complex and its Lifetime


A full-dimensional global potential energy surface for the KRb + KRb → K2 + Rb2 reaction is developed from 20 »759 ab initio points calculated using a coupled cluster singles, doubles, and perturbative triples (CCSD(T)) method with effective core potentials, extrapolated to the complete basis set limit. The ab initio points are represented with high fidelity (root-mean-square error of 1.86 cm-1) using the permutation-invariant polynomial-neural network method, which enforces the permutation invariance of the potential with respect to exchange of identical nuclei. The potential energy surface features two D2h minima and one Cs minimum connected by the isomerization saddle points. The Rice-Ramsperger-Kassel-Marcus lifetime of the K2Rb2 reaction intermediate estimated using the potential energy surface is 227 ns, in reasonable agreement with the latest experimental measurement.




This work was supported by the National Natural Science Foundation of China (Grants 21733006 and 21590802 to D.X.), by a MURI grant from Army Research Office (Grant W911NF-19-1-0283 to H.G.), and by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (Award DE-SC0019740 to R.D.).

Keywords and Phrases

Binary alloys; Mean square error; Molecular physics; Numerical methods; Potential energy; Potential energy surfaces; Quantum chemistry; Reaction intermediates; Rubidium alloys, Complete basis set limit; Coupled-cluster singles; Effective core potential; Global potential energy surfaces; High-fidelity; Invariant polynomials; Rice-ramsperger-kassel-marcus; Root mean square errors, Potassium alloys, ab initio calculation; article; isomerization; nonhuman; rice

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 2020 American Chemical Society (ACS), All rights reserved.

Publication Date

02 Apr 2020