### Abstract

We study vibrational deactivation processes on chemically reactive potential energy surfaces by examining accurate quantum mechanical transition probabilities and rate constants for the collinear H + FH(υ), D + FD(υ), H + FD(υ), and D + FH(υ) reactions. A low barrier (1.7 kcal/mole) potential surface is used in these calculations, and we find that for all four reactions, the reactive inelastic rate constants are larger than the nonreactive ones for the same initial and final vibrational states. However, the ratios of these reactive and nonreactive rate constants depend strongly on the vibrational quantum number υ and the isotopic composition of the reagents. Nonreactive and reactive transition probabilities for multiquantum jump transitions are generally comparable to those for single quantum transitions. This vibrationally nonadiabatic behavior is a direct consequence of the severe distortion of the diatomic that occurs in a collision on a low barrier reactive surface, and can make chemically reactive atoms like H or D more efficient deactivators of HF or DF than nonreactive collision partners. Many conclusions are in at least qualitative agreement with those of Wilkin's three dimensional quasiclassical trajectory study on the same systems using a similar surface. We also present results for H + HF(υ) collisions which show that for a higher barrier potential surface (33 rather than 1.7 kcal/mole), the deactivation process becomes similar in character to that for nonreactive partners, with υ→υ - 1 processes dominating.

Original language | English |
---|---|

Pages (from-to) | 2737-2743 |

Number of pages | 7 |

Journal | Journal of Chemical Physics |

Volume | 72 |

Issue number | 4 |

Publication status | Published - 1980 |

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### ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics

### Cite this

**Vibrational deactivation on chemically reactive potential surfaces : An exact quantum study of a low barrier collinear model of H + FH, D + FD, H + FD, and D + FH.** / Schatz, George C; Kuppermann, Aron.

Research output: Contribution to journal › Article

*Journal of Chemical Physics*, vol. 72, no. 4, pp. 2737-2743.

}

TY - JOUR

T1 - Vibrational deactivation on chemically reactive potential surfaces

T2 - An exact quantum study of a low barrier collinear model of H + FH, D + FD, H + FD, and D + FH

AU - Schatz, George C

AU - Kuppermann, Aron

PY - 1980

Y1 - 1980

N2 - We study vibrational deactivation processes on chemically reactive potential energy surfaces by examining accurate quantum mechanical transition probabilities and rate constants for the collinear H + FH(υ), D + FD(υ), H + FD(υ), and D + FH(υ) reactions. A low barrier (1.7 kcal/mole) potential surface is used in these calculations, and we find that for all four reactions, the reactive inelastic rate constants are larger than the nonreactive ones for the same initial and final vibrational states. However, the ratios of these reactive and nonreactive rate constants depend strongly on the vibrational quantum number υ and the isotopic composition of the reagents. Nonreactive and reactive transition probabilities for multiquantum jump transitions are generally comparable to those for single quantum transitions. This vibrationally nonadiabatic behavior is a direct consequence of the severe distortion of the diatomic that occurs in a collision on a low barrier reactive surface, and can make chemically reactive atoms like H or D more efficient deactivators of HF or DF than nonreactive collision partners. Many conclusions are in at least qualitative agreement with those of Wilkin's three dimensional quasiclassical trajectory study on the same systems using a similar surface. We also present results for H + HF(υ) collisions which show that for a higher barrier potential surface (33 rather than 1.7 kcal/mole), the deactivation process becomes similar in character to that for nonreactive partners, with υ→υ - 1 processes dominating.

AB - We study vibrational deactivation processes on chemically reactive potential energy surfaces by examining accurate quantum mechanical transition probabilities and rate constants for the collinear H + FH(υ), D + FD(υ), H + FD(υ), and D + FH(υ) reactions. A low barrier (1.7 kcal/mole) potential surface is used in these calculations, and we find that for all four reactions, the reactive inelastic rate constants are larger than the nonreactive ones for the same initial and final vibrational states. However, the ratios of these reactive and nonreactive rate constants depend strongly on the vibrational quantum number υ and the isotopic composition of the reagents. Nonreactive and reactive transition probabilities for multiquantum jump transitions are generally comparable to those for single quantum transitions. This vibrationally nonadiabatic behavior is a direct consequence of the severe distortion of the diatomic that occurs in a collision on a low barrier reactive surface, and can make chemically reactive atoms like H or D more efficient deactivators of HF or DF than nonreactive collision partners. Many conclusions are in at least qualitative agreement with those of Wilkin's three dimensional quasiclassical trajectory study on the same systems using a similar surface. We also present results for H + HF(υ) collisions which show that for a higher barrier potential surface (33 rather than 1.7 kcal/mole), the deactivation process becomes similar in character to that for nonreactive partners, with υ→υ - 1 processes dominating.

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M3 - Article

AN - SCOPUS:0001430249

VL - 72

SP - 2737

EP - 2743

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 4

ER -