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Electron correlation in the interacting quantum atoms partition via coupled‐cluster lagrangian densities
Author(s) -
HolguínGallego Fernando José,
ChávezCalvillo Rodrigo,
GarcíaRevilla Marco,
Francisco Evelio,
Pendás Ángel Martín,
RochaRinza Tomás
Publication year - 2016
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.24372
Subject(s) - coupled cluster , partition (number theory) , electronic correlation , chemistry , van der waals force , wave function , quantum chemistry , quantum , cluster (spacecraft) , electron , density functional theory , quantum mechanics , physics , atomic physics , statistical physics , computational chemistry , molecule , mathematics , computer science , combinatorics , programming language , supramolecular chemistry
The electronic energy partition established by the Interacting Quantum Atoms (IQA) approach is an important method of wavefunction analyses which has yielded valuable insights about different phenomena in physical chemistry. Most of the IQA applications have relied upon approximations, which do not include either dynamical correlation (DC) such as Hartree‐Fock (HF) or external DC like CASSCF theory. Recently, DC was included in the IQA method by means of HF/Coupled‐Cluster (CC) transition densities (Chávez‐Calvillo et al., Comput. Theory Chem . 2015, 1053 , 90). Despite the potential utility of this approach, it has a few drawbacks, for example, it is not consistent with the calculation of CC properties different from the total electronic energy. To improve this situation, we have implemented the IQA energy partition based on CC Lagrangian one‐ and two‐electron orbital density matrices. The development presented in this article is tested and illustrated with the H 2 , LiH, H 2 O, H 2 S, N 2 , and CO molecules for which the IQA results obtained under the consideration of (i) the CC Lagrangian, (ii) HF/CC transition densities, and (iii) HF are critically analyzed and compared. Additionally, the effect of the DC in the different components of the electronic energy in the formation of the T‐shaped (H 2 ) 2 van der Waals cluster and the bimolecular nucleophilic substitution between F – and CH 3 F is examined. We anticipate that the approach put forward in this article will provide new understandings on subjects in physical chemistry wherein DC plays a crucial role like molecular interactions along with chemical bonding and reactivity. © 2016 Wiley Periodicals, Inc.