Global potential energy surfaces (PESs) for the 1 »2A′ and 1 2A″ states of the C2N system responsible for the N(4Su) + C2(a 3Πu) → CN(X 2ς+) + C(3Pg) reaction are mapped using compressed-state multistate pair-density functional theory (CMS-PDFT), which is a multi-state version of multiconfiguration pair-density functional theory (MC-PDFT). Calculations are also performed at selected geometries by explicitly correlated multireference configuration interaction with quadruple corrections, MRCI-F12+Q, and the comparison of the two sets of calculations shows that CMS-PDFT describes the globally reactive PESs well, including the bond-breaking asymptotes. We conclude that CMS-PDFT is an efficient method for constructing PESs for strongly correlated reactive systems. The PESs for producing CN + C are found to be barrierless and proceed through intermediate complexes. The CMS-PDFT PESs were fitted with a neural network method, and quasiclassical trajectories were computed on the resulting analytic PESs. These trajectories predict that the reaction produces vibrationally excited CN.
Bibliographical noteFunding Information:
This work was supported by NASA (grant 80NSSC21K1117 to HG) and by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under award DE-SC0015997. The authors acknowledge the Center for Advanced Research Computing (CARC) at UNM and the Minnesota Supercomputing Institute.
© 2022 American Chemical Society. All rights reserved.
PubMed: MeSH publication types
- Journal Article