Concerted electron and proton transfer: Transition from nonadiabatic to adiabatic proton tunneling

Georgievskii, Yuri; Stuchebrukhov, Alexei A.

doi:doi:10.1063/1.1323723

Volume/Page
Keyword
DOI
Citation
Advanced

Volume: Page/Article:

Search Content Type

article doi:

Citation:

High order finite difference algorithms for solving the Schrödinger equation in molecular dynamics. II. Periodic variables

Variable high order finite difference methods are applied to calculate the action of molecular Hamiltonians on the wave function using centered equi-spaced stencils, mixed centered and one-sided stencils, and periodic Chebyshev and Legendre grids for the angular variables. Results from one-dimensional model Hamiltonians and the three-dimensional spectroscopic potential of SO2 demonstrate that as the order of finite difference approximations of the derivatives increases the accuracy of pseudospec...

Scaling reduction of the perturbative triples correction (T) to coupled cluster theory via Laplace transform formalism

A reformulation of the perturbative triples correction to coupled cluster singles and doubles (CCSD) based on the numerical Laplace transform of the energy denominator is presented. Rearranged equations reduce the O(N7) canonical scaling to O(N6), where N is a size measure of the electronic system. Two to three quadrature points is adequate for chemical predictions. The Laplace ansatz permits simple, noniterative expressions in noncanonical orbital representations. Furthermore, substituting cano...

A concerted electron–proton transfer reaction is discussed, in which proton tunneling occurs simultaneously with electronic transition. It is assumed that the potential in which the proton moves is formed by two electronic states, which in the absence of their interaction would cross in the region between the two minima of the proton adiabatic potential. The proton tunneling between the two wells is, therefore, coupled to a switch between the two electronic states. The later occurs only when the proton is in the tunneling region under the barrier. A simple analytical expression for the tunneling matrix element T_DA is derived, which is uniformly correct for small and large values of the electronic coupling. For small electronic coupling our expression coincides with that obtained in the nonadiabatic theory of proton-coupled electron transfer reactions. For large electronic coupling the expression is reduced to that obtained in the Born–Oppenheimer approximation. The transition from nonadiabatic to adiabatic tunneling is governed by the magnitude of the Landau–Zener parameter defined for the tunneling process. The obtained result is discussed in the context of the proton tunneling time. © 2000 American Institute of Physics.

RELATED DATABASES

To view database links for this article, you need to log in.

KEYWORDS and PACS

Keywords

charge exchange, chemical exchanges, tunnelling

PACS

82.30.Fi

Ion-molecule, ion-ion, and charge-transfer reactions
82.30.Hk

Chemical exchanges (substitution, atom transfer, abstraction, disproportionation, and group exchange)