Intrinsic Resolution of Molecular Electronic Wave Functions and Energies in Terms of Quasiatoms and Their Interactions
A general intrinsic energy resolution has been formulated for strongly correlated wave functions in the full molecular valence space and its subspaces. The information regarding the quasiatomic organization of the molecular electronic structure is extracted from the molecular wave function without introducing any additional postulated model state wave functions. To this end, the molecular wave function is expressed in terms of quasiatomic molecular orbitals, which maximize the overlap between subspaces of the molecular orbital space and the freeatom orbital spaces. As a result, the molecular wave function becomes the superposition of a wave function representing the nonbonded juxtaposed quasiatoms and a wave function describing the interatomic electron migrations that create bonds through electron sharing. The juxtaposed nonbonded quasiatoms are shown to consist of entangled quasiatomic states from different atoms. The binding energy is resolved as a sum of contributions that are due to quasiatom formation, quasiclassical electrostatic interactions and interatomic interferences caused by electron sharing. The contributions are further resolved according to orbital interactions. The various transformations that generate the analysis are determined by criteria that are independent of the working orbital basis used for calculating the molecular wave function. Lastly, the theoretical formulation of the resolution is quantitatively validatedmore »
 Authors:

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 Ames Lab. and Iowa State Univ., Ames, IA (United States). Dept. of Chemistry
 Publication Date:
 Report Number(s):
 ISJ9300
Journal ID: ISSN 10895639
 Grant/Contract Number:
 CHE1147446; CHE1565888; AC0207CH11358
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
 Additional Journal Information:
 Journal Volume: 121; Journal Issue: 5; Journal ID: ISSN 10895639
 Publisher:
 American Chemical Society
 Research Org:
 Ames Laboratory (AMES), Ames, IA (United States)
 Sponsoring Org:
 USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC22)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
 OSTI Identifier:
 1355451
West, Aaron C., Schmidt, Michael W., Gordon, Mark S., and Ruedenberg, Klaus. Intrinsic Resolution of Molecular Electronic Wave Functions and Energies in Terms of Quasiatoms and Their Interactions. United States: N. p.,
Web. doi:10.1021/acs.jpca.6b10911.
West, Aaron C., Schmidt, Michael W., Gordon, Mark S., & Ruedenberg, Klaus. Intrinsic Resolution of Molecular Electronic Wave Functions and Energies in Terms of Quasiatoms and Their Interactions. United States. doi:10.1021/acs.jpca.6b10911.
West, Aaron C., Schmidt, Michael W., Gordon, Mark S., and Ruedenberg, Klaus. 2017.
"Intrinsic Resolution of Molecular Electronic Wave Functions and Energies in Terms of Quasiatoms and Their Interactions". United States.
doi:10.1021/acs.jpca.6b10911. https://www.osti.gov/servlets/purl/1355451.
@article{osti_1355451,
title = {Intrinsic Resolution of Molecular Electronic Wave Functions and Energies in Terms of Quasiatoms and Their Interactions},
author = {West, Aaron C. and Schmidt, Michael W. and Gordon, Mark S. and Ruedenberg, Klaus},
abstractNote = {A general intrinsic energy resolution has been formulated for strongly correlated wave functions in the full molecular valence space and its subspaces. The information regarding the quasiatomic organization of the molecular electronic structure is extracted from the molecular wave function without introducing any additional postulated model state wave functions. To this end, the molecular wave function is expressed in terms of quasiatomic molecular orbitals, which maximize the overlap between subspaces of the molecular orbital space and the freeatom orbital spaces. As a result, the molecular wave function becomes the superposition of a wave function representing the nonbonded juxtaposed quasiatoms and a wave function describing the interatomic electron migrations that create bonds through electron sharing. The juxtaposed nonbonded quasiatoms are shown to consist of entangled quasiatomic states from different atoms. The binding energy is resolved as a sum of contributions that are due to quasiatom formation, quasiclassical electrostatic interactions and interatomic interferences caused by electron sharing. The contributions are further resolved according to orbital interactions. The various transformations that generate the analysis are determined by criteria that are independent of the working orbital basis used for calculating the molecular wave function. Lastly, the theoretical formulation of the resolution is quantitatively validated by an application to the C2 molecule.},
doi = {10.1021/acs.jpca.6b10911},
journal = {Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory},
number = 5,
volume = 121,
place = {United States},
year = {2017},
month = {1}
}