# Barrierless association of CF _{2} and dissociation of C _{2}F _{4} by variational transition-state theory and system-specific quantum Rice–Ramsperger–Kassel theory

## Abstract

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 (C _{2}F _{4}), 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. In conclusion, our computed dissociation rate constants agree well with the recent experimental measurements.

- Authors:

- Beijing Univ. of Chemical Technology, Beijing (People's Republic of China); Univ. of Minnesota, Minneapolis, MN (United States)
- Univ. of Minnesota, Minneapolis, MN (United States)

- Publication Date:

- Research Org.:
- Univ. of Minnesota, Minneapolis, MN (United States); Univ. of New Mexico, Albuquerque, NM (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)

- OSTI Identifier:
- 1465484

- Grant/Contract Number:
- FG02-86ER13579; SC0015997

- Resource Type:
- Journal Article: Accepted Manuscript

- Journal Name:
- Proceedings of the National Academy of Sciences of the United States of America

- Additional Journal Information:
- Journal Volume: 113; Journal Issue: 48; Journal ID: ISSN 0027-8424

- Publisher:
- National Academy of Sciences, Washington, DC (United States)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; bond dissociation; barrierless reaction; variable-reaction-coordinate variational transition-state theory; falloff; system-specific quantum RRK theory

### Citation Formats

```
Bao, Junwei Lucas, Zhang, Xin, and Truhlar, Donald G.
```*Barrierless association of CF2 and dissociation of C2F4 by variational transition-state theory and system-specific quantum Rice–Ramsperger–Kassel theory*. United States: N. p., 2016.
Web. doi:10.1073/pnas.1616208113.

```
Bao, Junwei Lucas, Zhang, Xin, & Truhlar, Donald G.
```*Barrierless association of CF2 and dissociation of C2F4 by variational transition-state theory and system-specific quantum Rice–Ramsperger–Kassel theory*. United States. doi:10.1073/pnas.1616208113.

```
Bao, Junwei Lucas, Zhang, Xin, and Truhlar, Donald G. Thu .
"Barrierless association of CF2 and dissociation of C2F4 by variational transition-state theory and system-specific quantum Rice–Ramsperger–Kassel theory". United States.
doi:10.1073/pnas.1616208113. https://www.osti.gov/servlets/purl/1465484.
```

```
@article{osti_1465484,
```

title = {Barrierless association of CF2 and dissociation of C2F4 by variational transition-state theory and system-specific quantum Rice–Ramsperger–Kassel theory},

author = {Bao, Junwei Lucas and Zhang, Xin and Truhlar, Donald G.},

abstractNote = {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. In conclusion, our computed dissociation rate constants agree well with the recent experimental measurements.},

doi = {10.1073/pnas.1616208113},

journal = {Proceedings of the National Academy of Sciences of the United States of America},

number = 48,

volume = 113,

place = {United States},

year = {Thu Nov 10 00:00:00 EST 2016},

month = {Thu Nov 10 00:00:00 EST 2016}

}

*Citation information provided by*

Web of Science

Web of Science

Works referenced in this record:

##
Self-Consistent Equations Including Exchange and Correlation Effects

journal, November 1965

- Kohn, W.; Sham, L. J.
- Physical Review, Vol. 140, Issue 4A, p. A1133-A1138

##
A new local density functional for main-group thermochemistry, transition metal bonding, thermochemical kinetics, and noncovalent interactions

journal, November 2006

- Zhao, Yan; Truhlar, Donald G.
- The Journal of Chemical Physics, Vol. 125, Issue 19, Article No. 194101