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Electronic structure benchmark calculations of inorganic and biochemical carboxylation reactions
Author(s) -
DouglasGallardo Oscar A.,
Saez David Adrian,
VogtGeisse Stefan,
VöhringerMartinez Esteban
Publication year - 2019
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.25795
Subject(s) - electronic structure , chemistry , carboxylation , electronic correlation , molecule , computational chemistry , density functional theory , ab initio , context (archaeology) , basis set , atomic orbital , electron , physics , quantum mechanics , organic chemistry , paleontology , biology , catalysis
Carboxylation reactions represent a very special class of chemical reactions that is characterized by the presence of a carbon dioxide (CO 2 ) molecule as reactive species within its global chemical equation. These reactions work as fundamental gear to accomplish the CO 2 fixation and thus to build up more complex molecules through different technological and biochemical processes. In this context, a correct description of the CO 2 electronic structure turns out to be crucial to study the chemical and electronic properties associated with this kind of reactions. Here, a systematic study of CO 2 electronic structure and its contribution to different carboxylation reaction electronic energies has been carried out by means of several high‐level ab initio post‐Hartree Fock (post‐HF) and density functional theory (DFT) calculations for a set of biochemistry and inorganic systems. We have found that for a correct description of the CO 2 electronic correlation energy it is necessary to include post‐CCSD(T) contributions (beyond the gold standard). These high‐order excitations are required to properly describe the interactions of the four π ‐electrons associated with the two degenerated π ‐molecular orbitals of the CO 2 molecule. Likewise, our results show that in some reactions it is possible to obtain accurate reaction electronic energy values with computationally less demanding methods when the error in the electronic correlation energy compensates between reactants and products. Furthermore, the provided post‐HF reference values allowed to validating different DFT exchange‐correlation functionals combined with different basis sets for chemical reactions that are relevant in biochemical CO 2 fixing enzymes. © 2019 Wiley Periodicals, Inc.