Natural bond orbitals in multiconfigurational expansions: Local treatment of electron correlation in molecules

AbstractDensity-functional theory (DFT) is a rigorous and (in principle) exact framework for the description of the ground state properties of atoms, molecules and solids based on their electron density. While computationally efficient density-functional approximations (DFAs) have become essential tools in computational chemistry, their (semi-)local treatment of electron correlation has a number of well-known pathologies, e.g. related to electron self-interaction. Here, we present a type of machine-learning (ML) based DFA (termed Kernel Density Functional Approximation, KDFA) that is pure, non-local and transferable, and can be efficiently trained with fully quantitative reference methods. The functionals retain the mean-field computational cost of common DFAs and are shown to be applicable to non-covalent, ionic and covalent interactions, as well as across different system sizes. We demonstrate their remarkable possibilities by computing the free energy surface for the protonated water dimer at hitherto unfeasible gold-standard coupled cluster quality on a single commodity workstation.

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Local Treatment of Electron Correlation

Annual Review of Physical Chemistry ◽

10.1146/annurev.pc.44.100193.001241 ◽

1993 ◽

Vol 44 (1) ◽

pp. 213-236 ◽

Cited By ~ 501

Author(s):

S Saebo ◽

P Pulay

Keyword(s):

Electron Correlation ◽

Local Treatment

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ChemInform Abstract: Local Treatment of Electron Correlation in Molecular Clusters: Structures and Stabilities of (H2O)n, n = 2-4.

ChemInform ◽

10.1002/chin.199838002 ◽

2010 ◽

Vol 29 (38) ◽

pp. no-no

Author(s):

M. SCHUETZ ◽

G. RAUHUT ◽

H.-J. WERNER

Keyword(s):

Electron Correlation ◽

Local Treatment ◽

Molecular Clusters

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Local treatment of electron correlation in coupled cluster theory

The Journal of Chemical Physics ◽

10.1063/1.471289 ◽

1996 ◽

Vol 104 (16) ◽

pp. 6286-6297 ◽

Cited By ~ 592

Author(s):

Claudia Hampel ◽

Hans‐Joachim Werner

Keyword(s):

Electron Correlation ◽

Local Treatment ◽

Coupled Cluster ◽

Coupled Cluster Theory ◽

Cluster Theory

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To What Extent are Inelastically Scattered Electrons Useful in the Stem?

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071879 ◽

1973 ◽

Vol 31 ◽

pp. 286-287 ◽

Cited By ~ 2

Author(s):

H. Rose

Keyword(s):

Electron Microscope ◽

High Resolution ◽

Electron Correlation ◽

Quantum Noise ◽

Collection Efficiency ◽

Scanning Transmission Electron Microscope ◽

Electron Cloud ◽

Scanning Time ◽

Transmission Electron ◽

Scanning Transmission

The scanning transmission electron microscope offers the possibility of utilizing inelastically scattered electrons. Use of these electrons in addition to the elastically scattered electrons should reduce the scanning time (dose) Which is necessary to keep the quantum noise below a certain level. Hence it should lower the radiation damage. For high resolution, Where the collection efficiency of elastically scattered electrons is small, the use of Inelastically scattered electrons should become more and more favorable because they can all be detected by means of a spectrometer. Unfortunately, the Inelastic scattering Is a non-localized interaction due to the electron-electron correlation, occurring predominantly at the circumference of the atomic electron cloud.

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