The Use of Explicitly Correlated Methods on XeF6 Predicts a C3v Minimum with a Sterically Active, Free Valence Electron Pair on Xe

The S66 benchmark for non-covalent interactions has been re-evaluated using explicitly correlated methods with basis sets near the one-particle basis set limit. It is found that post-MP2 ‘high-level corrections’ are treated adequately well using a combination of CCSD(F12*) with (aug-)cc-pVTZ-F12 basis sets on the one hand, and (T) extrapolated from conventional CCSD(T)/heavy-aug-cc-pV{D,T}Z on the other hand. Implications for earlier benchmarks on the larger S66×8 problem set in particular, and for accurate calculations on non-covalent interactions in general, are discussed. At a slight cost in accuracy, (T) can be considerably accelerated by using sano-V{D,T}Z+ basis sets, whereas half-counterpoise CCSD(F12*)(T)/cc-pVDZ-F12 offers the best compromise between accuracy and computational cost.

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EXPANSION FORMULAE FOR ONE- AND TWO-CENTER CHARGE DENSITIES OVER COMPLETE ORTHONORMAL SETS OF EXPONENTIAL TYPE ORBITALS AND THEIR USE IN EVALUATION OF MULTICENTER–MULTIELECTRON INTEGRALS

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633609004940 ◽

2009 ◽

Vol 08 (04) ◽

pp. 597-602 ◽

Cited By ~ 3

Author(s):

I. I. GUSEINOV

Keyword(s):

Exponential Type ◽

Overlap Integrals ◽

Charge Densities ◽

Hartree Fock ◽

Expansion Formulae ◽

Multicenter Multielectron Integrals ◽

Explicitly Correlated ◽

Explicitly Correlated Methods ◽

Exponential Type Orbitals ◽

The One

The series expansion formulae are established for the one- and two-center charge densities over complete orthonormal sets of Ψα-exponential type orbitals (Ψα-ETO α = 1,0,-1,-2,…) introduced by the author. Three-center overlap integrals of Ψα appearing in these relations are expressed through the two-center overlap integrals between Ψα-orbitals. The general formulae obtained for the charge densities are utilized for the evaluation of arbitrary multicenter–multielectron integrals occurring when the complete orthonormal sets of Ψα-ETO are used as basis functions in the Hartree–Fock–Roothaan and explicitly correlated methods. The relationships for charge densities and multicenter–multielectron integrals obtained are valid for the arbitrary quantum numbers, screening constants, and location of Ψα-orbitals.

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Optimized auxiliary basis sets for explicitly correlated methods

The Journal of Chemical Physics ◽

10.1063/1.3009271 ◽

2008 ◽

Vol 129 (18) ◽

pp. 184108 ◽

Cited By ~ 328

Author(s):

Kazim E. Yousaf ◽

Kirk A. Peterson

Keyword(s):

Basis Sets ◽

Explicitly Correlated ◽

Explicitly Correlated Methods

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Steric activity of the central atom free valence electron pairs in free hexafluorobromate(1-) and hexafluoroiodate(1-) ions

Inorganic Chemistry ◽

10.1021/ic00316a001 ◽

1989 ◽

Vol 28 (17) ◽

pp. 3275-3277 ◽

Cited By ~ 31

Author(s):

Karl O. Christe ◽

William W. Wilson

Keyword(s):

Valence Electron ◽

Central Atom ◽

Free Valence ◽

Electron Pairs

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ChemInform Abstract: Steric Activity of the Central Atom Free Valence Electron Pairs in Free BrF- 6 and IF- 6 Ions.

ChemInform ◽

10.1002/chin.198948001 ◽

1989 ◽

Vol 20 (48) ◽

Author(s):

K. O. CHRISTE ◽

W. W. WILSON

Keyword(s):

Valence Electron ◽

Central Atom ◽

Free Valence ◽

Electron Pairs

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The Valence Electron Structure of High-Entropy Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1142.3 ◽

2017 ◽

Vol 1142 ◽

pp. 3-7

Author(s):

Bo Cheng ◽

Yun Kai Li ◽

Gui Qin Hou

Keyword(s):

Valence Electron ◽

Electron Pair ◽

Electron Structure ◽

High Entropy Alloys ◽

Electron Theory ◽

Valence Electron Structure ◽

High Entropy ◽

Melting Temperatures ◽

Empirical Electron Theory ◽

Pair Number

Empirical Electron Theory in Solids and Molecules (EET) was used to analyze the valence electron structure of ZrTiHfVNb, ZrTiHfVTa and ZrTiHfNbMo high-entropy alloys. The parameters characterizing the valence electron structure of high-entropy alloys were calculated, which were used to discuss the hardness and melting temperature of high-entropy alloys. The results show that the hardness of high-entropy alloys is positively correlated to the shared electron pair number in valence electron structure. The theoretical melting temperatures of high-entropy alloys were predicted by the parameters characterizing the valence electron structure.

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