Modern valence bond representations of CASSCF wavefunctions

T  Thorsteinsson; D L  Cooper; J  Gerratt; P B  Karadakov; M  Raimondi

Modern valence bond representations of CASSCF wavefunctions

T Thorsteinsson, D L Cooper, J Gerratt, P B Karadakov, M Raimondi

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

Exact transformations of ''N electrons in N orbitals'' CASSCF structure spaces are examined that lead to modern valence bond representations, in which the total wavefunction is dominated by covalent structures built from a common product of nonorthogonal orbitals. The resulting descriptions of the electronic structure may be compared directly with those that arise in the spin-coupled (or full-GVB) approach. Using singlet methylene, methane and ozone as representative examples, various overlap-based and energy-based criteria are investigated for generating modern VB representations of ''N in N'' CASSCF wavefunctions, which we denote CASVB.

Original language	English
Pages (from-to)	343-366
Number of pages	24
Journal	THEORETICA CHIMICA ACTA
Volume	93
Issue number	6
Publication status	Published - Jun 1996

Keywords

CASSCF
spin-coupled
VB
CASVB
MOLECULAR ELECTRONIC WAVEFUNCTIONS
WAVE-FUNCTIONS
FORS MODEL
ATOMS
CONVERGENCE
1,3-DIPOLES
METHYLENE
ORBITALS
SPACE
CH2

Cite this

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title = "Modern valence bond representations of CASSCF wavefunctions",

abstract = "Exact transformations of ''N electrons in N orbitals'' CASSCF structure spaces are examined that lead to modern valence bond representations, in which the total wavefunction is dominated by covalent structures built from a common product of nonorthogonal orbitals. The resulting descriptions of the electronic structure may be compared directly with those that arise in the spin-coupled (or full-GVB) approach. Using singlet methylene, methane and ozone as representative examples, various overlap-based and energy-based criteria are investigated for generating modern VB representations of ''N in N'' CASSCF wavefunctions, which we denote CASVB.",

keywords = "CASSCF, spin-coupled, VB, CASVB, MOLECULAR ELECTRONIC WAVEFUNCTIONS, WAVE-FUNCTIONS, FORS MODEL, ATOMS, CONVERGENCE, 1,3-DIPOLES, METHYLENE, ORBITALS, SPACE, CH2",

author = "T Thorsteinsson and Cooper, {D L} and J Gerratt and Karadakov, {P B} and M Raimondi",

year = "1996",

month = jun,

language = "English",

volume = "93",

pages = "343--366",

journal = "THEORETICA CHIMICA ACTA",

issn = "0040-5744",

publisher = "Springer",

number = "6",

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TY - JOUR

T1 - Modern valence bond representations of CASSCF wavefunctions

AU - Thorsteinsson, T

AU - Cooper, D L

AU - Gerratt, J

AU - Karadakov, P B

AU - Raimondi, M

PY - 1996/6

Y1 - 1996/6

N2 - Exact transformations of ''N electrons in N orbitals'' CASSCF structure spaces are examined that lead to modern valence bond representations, in which the total wavefunction is dominated by covalent structures built from a common product of nonorthogonal orbitals. The resulting descriptions of the electronic structure may be compared directly with those that arise in the spin-coupled (or full-GVB) approach. Using singlet methylene, methane and ozone as representative examples, various overlap-based and energy-based criteria are investigated for generating modern VB representations of ''N in N'' CASSCF wavefunctions, which we denote CASVB.

AB - Exact transformations of ''N electrons in N orbitals'' CASSCF structure spaces are examined that lead to modern valence bond representations, in which the total wavefunction is dominated by covalent structures built from a common product of nonorthogonal orbitals. The resulting descriptions of the electronic structure may be compared directly with those that arise in the spin-coupled (or full-GVB) approach. Using singlet methylene, methane and ozone as representative examples, various overlap-based and energy-based criteria are investigated for generating modern VB representations of ''N in N'' CASSCF wavefunctions, which we denote CASVB.

KW - CASSCF

KW - spin-coupled

KW - VB

KW - CASVB

KW - MOLECULAR ELECTRONIC WAVEFUNCTIONS

KW - WAVE-FUNCTIONS

KW - FORS MODEL

KW - ATOMS

KW - CONVERGENCE

KW - 1,3-DIPOLES

KW - METHYLENE

KW - ORBITALS

KW - SPACE

KW - CH2

M3 - Article

SN - 0040-5744

VL - 93

SP - 343

EP - 366

JO - THEORETICA CHIMICA ACTA

JF - THEORETICA CHIMICA ACTA

IS - 6

ER -