One-Electron Properties of Near-Hartree–Fock Wavefunctions. I. Water

Neumann, D.; Moskowitz, Jules W.

doi:10.1063/1.1670367

Cited by 288 publications

(36 citation statements)

References 52 publications

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“…In the light of this we shall expect to compute a rather poor value for the electric polarizability. The dipole moment can be improved using the more ' flexible ' [5s3p2d/2slp] wave function of Neumann and Moskowitz [9] ; note however, that a corresponding improvement is not obtained for the quadrupole moment tensor, see table 2.…”

Section: Calculationsmentioning

confidence: 97%

“…Throughout this paper we express all molecular quantities in atomic units ; the conversion to ' experimental ' and S I units is given in table 1. The total SCF energy corresponding to this geometry was -76.051 977 hartree, this energy is off by 0-0013 hartree from the theoretical minimum value [2] which in turn is believed to be up to 0-03 hartree above the Hartree-Fock limit [2,9].…”

Section: Calculationsmentioning

confidence: 97%

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Calculation of molecular one-electron properties using coupled Hartree-Fock methods

Thomsen

Swanstrøm

1973

Molecular Physics

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Section: Calculationsmentioning

confidence: 97%

Section: Calculationsmentioning

confidence: 97%

Calculation of molecular one-electron properties using coupled Hartree-Fock methods

Thomsen

Swanstrøm

1973

Molecular Physics

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“…The one electron properties package for Gaussians written by Neumann and Moskowitz [36] was used with only minor local modifications.…”

Section: Computational Detailsmentioning

confidence: 99%

The generalized separated electron pair model. 1. An application to NH₃

Robb

Csizmadia

1970

Int J of Quantum Chemistry

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AbstractsThe utility of the separated electron pair (SEP) model (strongly orthogonal geminals) is examined quantitatively, for pyramidal and planar nuclear configurations of the NH, molecule. The best SEP wave function computed for each species is capable of recovering about half of the correlation energy obtained by a fairly accurate configuration interaction (GI) calculation, (corresponding to roughly 2 5 O b of the total molecular correlation energy). I t is illustrated that the model can be systematically extended with only a modest effort to yield more accurate results (about 409, of the total correlation energy). The fact that the corrections to the SEP model have a simple physical interpretation suggests that this model may be a useful starting point for "brute force" CI calculations on larger chemical systems. O n examine d u point de vue quantitatif, I'utilitt d u modele des paires stpartes (SEP)pour les configurations nucltaires pyramidales et planes de la moltcule NH, . Avec la meilleure fonction d'onde SEP on retrouve B prts peu la moitit de l'tnergie d e corrtlation obtenue par un calcul d'interaction des configurations (CI) assez prCcis (correspondant B environ 2 5 O " de l'tnergie de corrtlation totale de la moltcule). O n niontre par une illustration que ce modtle peut &tre gtntralist d'une facon systtmatique avec un effort modeste, pour rendre des resultats plus prtcis (environ 40; ;de I'tnergie de correlation totale). Le fait que les corrections au modele SEP posstdent une interpretation physique simple suggere que ce modde-ci peut servir conime point de dtpart pour des calculs GI trts grands pour des systtmes chimiques plus grands.Die Brauchbarkeit des Modells mit getrennten Elektronenpaare (stark orthogonale Geminale) wird in quantitativer Weise fur pyramidale und ebene Kernkonfigurationen des NH,-Molekuls untersucht. Mit der besten sEP-b'ellenfunktion erhalt man ungefahr die Halfte der Korrelationsenergie, die man mit einer recht prazisen Konfigurationswechselwirkungsberechnung (GI) berechnen kann (ungefahr 2500 der totalen molekularen Korrelationsenergie). Es wird illustriert, dass das Modell in systematischer Weise verallgemeinert werden kann um prazisere Resultate (ungefahr 40" , , der totalen Korrelationsenergie) zu geben. Die Tatsache dass die Korrekturen des sEp-Modells eine einfache physikalische Bedeutung haben schlagt vor dass dieses Modell ein nutzlicher Ausgangspunkt ftir "brute force" cI-Berechnungen fur grossere chemische Systeme sein kann.

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“…But, even though it is only of theoretical interest, it must follow from this discussion that the product of the best correlation function in table 12, and the best S.C.F. determinant (I) calculated so far [11] is the best available wavefunction for the H~O molecule. From (64), its associated energy, calculated by the transcorrelated method is -76-324, to be compared with the estimated exact value of -76.43 A.U.…”

Section: Discussionmentioning

confidence: 98%

The transcorrelated method for accurate correlation energies using gaussian-type functions: examples on He, H₂, LiH and H₂O

Handy

1972

Molecular Physics

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The first transcorrelated calculations for correlated wavefunctions C(I) which use purely analytical integration methods are presented. If we write C= .1-!exp (GT(ri, rj)), where GT is a linear combination of functions z>J like exp (-arij e) and exp (-briBe), and q) is a Slater determinant whose orbital basis set is the usual gaussians, then Boys showed that all the integrals of the transcorrelated method could be evaluated. These are the bases used here. However, the use of a limited gaussian orbital basis set makes q) a bad approximation to the best determinant. The results in atomic units are (giving the S.C.F. energy WSCF= (qblH[~)/(q)[~) and the correlation energy We, with their exact values in parenthesis) : He : WseF= --2-710 (--2.862), We= -0"0399 (-0"0420), He : WseF= --0"976 (--1"133), We= -0"0419 (--0'0405), LiH : WSCF= --7-589 (--7-987), We= -0"0759 (--0"082), HeO : Wscr= -64"23 (-76'07), We= -0"254 (-0"364).Calculations were performed at the experimental geometry. A few threeelectron integrals used in the determination of parameters, but not in the determination of energies, were ignored in LiH and H20, but this is not thought to affect the nature of the results. The reason why the convergence of the energy in these calculations is much closer to variational-type convergence than in previous transcorrelated calculations is explained. These results give great potentiality for the method when bigger orbital basis sets are used, which is already possible with the faster computers now available.

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One-Electron Properties of Near-Hartree–Fock Wavefunctions. I. Water

Cited by 288 publications

References 52 publications

Calculation of molecular one-electron properties using coupled Hartree-Fock methods

Calculation of molecular one-electron properties using coupled Hartree-Fock methods

The generalized separated electron pair model. 1. An application to NH₃

The transcorrelated method for accurate correlation energies using gaussian-type functions: examples on He, H₂, LiH and H₂O

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One-Electron Properties of Near-Hartree–Fock Wavefunctions. I. Water

Cited by 288 publications

References 52 publications

Calculation of molecular one-electron properties using coupled Hartree-Fock methods

Calculation of molecular one-electron properties using coupled Hartree-Fock methods

The generalized separated electron pair model. 1. An application to NH3

The transcorrelated method for accurate correlation energies using gaussian-type functions: examples on He, H2, LiH and H2O

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The generalized separated electron pair model. 1. An application to NH₃

The transcorrelated method for accurate correlation energies using gaussian-type functions: examples on He, H₂, LiH and H₂O