A quantum theory of thermal reaction rates is presented which may be viewed as an extension of the recently developed "quantum instanton" (QI) model [W. H. Miller, Y. Zhao, M. Ceotto, and S. Yang, J. Chem. Phys. 119, 1329 (2003)]. It is based on using higher derivatives of the flux-flux autocorrelation function C(t) (as given by Miller, Schwartz, and Tromp) at t = 0 to construct a short time approximation for C(t). Tests of this theory on 1d and collinear reactions, both symmetric and asymmetric, show it to be more accurate than the original QI model, giving rate constants to ~5% for a wide range of temperature.
|Titolo:||Quantum reaction rate from higher derivatives of the thermal flux-flux autocorrelation function at time zero|
|Parole Chiave:||Transition-state theory; path-integral methods; mechanical rate constants; proton-transfer reactions; chemical-reaction rates; instanton approximation; collinear reactions; molecular-dynamics; polar environment; simulations|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Data di pubblicazione:||22-gen-2005|
|Digital Object Identifier (DOI):||10.1063/1.1839177|
|Appare nelle tipologie:||01 - Articolo su periodico|