Quantum information from selected elementary chemical reactions: Maximum entangled transition state

Abstract

Quantum entanglement features exhibited by the reaction path of some selected elementary chemical reactions: hydrogenic abstraction, nucleophilic hydrogenic substitution, three-atom insertion reaction of silylene into hydrogen, and the cycloaddition of cyclopentadiene into anhydride maleic are investigated in this work. The phenomenological behavior of these reactions is described by two of the fundamental descriptors of the molecular densities, the atomic charges, and the electric potentials, to associate the maximum entangled transition state (METS) to the concurrent processes of the chemical reactions. It is found that the METS characterizes the transition state of symmetrical reactions; and for nonsymmetrical ones, it features a new critical point along the intrinsic reaction path. In addition, benchmark calculations of the relevant quantitative entanglement measures for the critical points of these reactions are reported.