Nonadiabatic transition state theory

Nonadiabatic transition state theory (NA-TST) is a powerful tool to predict rates of chemical reactions from a computational standpoint. NA-TST has been introduced in 1988 by Prof. J.C. Lorquet.[1] In general, all of the assumptions taking place in traditional transition state theory (TST) are also used in NA-TST but with some corrections. First, a spin-forbidden reaction proceeds through the minimum energy crossing point (MECP) rather than through transition state (TS).[2] Second, unlike TST, the probability of transition is not equal to unity during the reaction and treated as a function of internal energy associated with the reaction coordinate.[3] At this stage non-relativistic couplings responsible for mixing between states is a driving force of transition. For example, the larger spin-orbit coupling at MECP the larger the probability of transition. NA-TST can be reduced to the traditional TST in the limit of unit probability.[3]


  1. ^ Lorquet, J. C.; Leyh-Nihant, B. (2002-05-01). "Nonadiabatic unimolecular reactions. 1. A statistical formulation for the rate constants". The Journal of Physical Chemistry. 92 (16): 4778–4783. doi:10.1021/j100327a043.
  2. ^ Harvey, Jeremy N. (2007-01-02). "Understanding the kinetics of spin-forbidden chemical reactions". Phys. Chem. Chem. Phys. 9 (3): 331–343. Bibcode:2007PCCP....9..331H. doi:10.1039/b614390c. ISSN 1463-9084. PMID 17199148.
  3. ^ a b Lykhin, Aleksandr O.; Kaliakin, Danil S.; dePolo, Gwen E.; Kuzubov, Alexander A.; Varganov, Sergey A. (2016-05-15). "Nonadiabatic transition state theory: Application to intersystem crossings in the active sites of metal-sulfur proteins". International Journal of Quantum Chemistry. 116 (10): 750–761. doi:10.1002/qua.25124. ISSN 1097-461X.