Barrierless association of CF2 and dissociation of C2F4 by variational transition-state theory and system-specific quantum Rice-Ramsperger-Kassel theory.
Bond dissociation is a fundamental chemical reaction, and the first principles modeling of the kinetics of dissociation reactions with a monotonically increasing potential energy along the dissociation coordinate presents a challenge not only for modern electronic structure methods but also for kinetics theory. In this work, we use multifaceted variable-reaction-coordinate variational transition-state theory (VRC-VTST) to compute the high-pressure limit dissociation rate constant of tetrafluoroethylene (C2F4), in which the potential energies are computed by direct dynamics with the M08-HX exchange correlation functional. To treat the pressure dependence of the unimolecular rate constants, we use the recently developed system-specific quantum Rice-Ramsperger-Kassel theory. The calculations are carried out by direct dynamics using an exchange correlation functional validated against calculations that go beyond coupled-cluster theory with single, double, and triple excitations. Our computed dissociation rate constants agree well with the recent experimental measurements.
State Key Laboratory of Chemical Resource Engineering, Institute of Materia Medica, College of Science, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.|Department of Chemistry, Chemical Theory Center, University of Minnesota, Minneapolis, MN 55455-0431.|Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455-0431.
Junwei Lucas
JL
Bao
State Key Laboratory of Chemical Resource Engineering, Institute of Materia Medica, College of Science, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China; zhangxin@mail.buct.edu.cn truhlar@umn.edu.|Department of Chemistry, Chemical Theory Center, University of Minnesota, Minneapolis, MN 55455-0431.|Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455-0431.
Xin
X
Zhang
Department of Chemistry, Chemical Theory Center, University of Minnesota, Minneapolis, MN 55455-0431; zhangxin@mail.buct.edu.cn truhlar@umn.edu.|Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455-0431.
Donald G
0000-0002-7742-7294
DG
Truhlar
barrierless reaction; bond dissociation; falloff; system-specific quantum RRK theory; variable-reaction-coordinate variational transition-state theory