Towards a molecular orbital method for the conformational analysis of very large biomolecules

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

A quantum chemical method is proposed for the conformational analysis of very large biomolecules. The total wave function is constructed of localized bond fragments each determined on the basis of chemical intuition and model calculations on small molecules. The transferability of bond orbitals, localized strictly onto a few atoms of the molecule is discussed. The Löwdin procedure is applied to obtain orthogonalized molecular orbitals. The energy expression is calculated using the ZDO assumption. Simplified formulas for the Coulombic-type electronic interaction integrals are introduced. This approximation is similar to the assumption of the CNDO-method made in order to maintain rotational invariance. To obtain an energy expression, containing a number of terms proportional to N2, (N is the number of occupied orbitals) the overlap of non-adjacent bond orbitals is neglected. At last a simple point-charge interaction is assumed to act between atoms lying far from each other. Thus the calculation of the energy involves the evaluation of a number of integrals proportional to the first power of N. Numerical results for H2, Li2 and LiH are given.

Original languageEnglish
Pages (from-to)261-273
Number of pages13
JournalActa Physica Academiae Scientiarum Hungaricae
Volume40
Issue number4
DOIs
Publication statusPublished - Apr 1976

Fingerprint

molecular orbitals
orbitals
atoms
energy
molecules
invariance
fragments
interactions
wave functions
evaluation
approximation
electronics

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

@article{aae15ffe196844e085ac23414a4cdc58,
title = "Towards a molecular orbital method for the conformational analysis of very large biomolecules",
abstract = "A quantum chemical method is proposed for the conformational analysis of very large biomolecules. The total wave function is constructed of localized bond fragments each determined on the basis of chemical intuition and model calculations on small molecules. The transferability of bond orbitals, localized strictly onto a few atoms of the molecule is discussed. The L{\"o}wdin procedure is applied to obtain orthogonalized molecular orbitals. The energy expression is calculated using the ZDO assumption. Simplified formulas for the Coulombic-type electronic interaction integrals are introduced. This approximation is similar to the assumption of the CNDO-method made in order to maintain rotational invariance. To obtain an energy expression, containing a number of terms proportional to N2, (N is the number of occupied orbitals) the overlap of non-adjacent bond orbitals is neglected. At last a simple point-charge interaction is assumed to act between atoms lying far from each other. Thus the calculation of the energy involves the evaluation of a number of integrals proportional to the first power of N. Numerical results for H2, Li2 and LiH are given.",
author = "G. N{\'a}ray-Szab{\'o}",
year = "1976",
month = "4",
doi = "10.1007/BF03157503",
language = "English",
volume = "40",
pages = "261--273",
journal = "Acta Physica Academiae Scientiarum Hungaricae",
issn = "0001-6705",
publisher = "Akademiai Kiado",
number = "4",

}

TY - JOUR

T1 - Towards a molecular orbital method for the conformational analysis of very large biomolecules

AU - Náray-Szabó, G.

PY - 1976/4

Y1 - 1976/4

N2 - A quantum chemical method is proposed for the conformational analysis of very large biomolecules. The total wave function is constructed of localized bond fragments each determined on the basis of chemical intuition and model calculations on small molecules. The transferability of bond orbitals, localized strictly onto a few atoms of the molecule is discussed. The Löwdin procedure is applied to obtain orthogonalized molecular orbitals. The energy expression is calculated using the ZDO assumption. Simplified formulas for the Coulombic-type electronic interaction integrals are introduced. This approximation is similar to the assumption of the CNDO-method made in order to maintain rotational invariance. To obtain an energy expression, containing a number of terms proportional to N2, (N is the number of occupied orbitals) the overlap of non-adjacent bond orbitals is neglected. At last a simple point-charge interaction is assumed to act between atoms lying far from each other. Thus the calculation of the energy involves the evaluation of a number of integrals proportional to the first power of N. Numerical results for H2, Li2 and LiH are given.

AB - A quantum chemical method is proposed for the conformational analysis of very large biomolecules. The total wave function is constructed of localized bond fragments each determined on the basis of chemical intuition and model calculations on small molecules. The transferability of bond orbitals, localized strictly onto a few atoms of the molecule is discussed. The Löwdin procedure is applied to obtain orthogonalized molecular orbitals. The energy expression is calculated using the ZDO assumption. Simplified formulas for the Coulombic-type electronic interaction integrals are introduced. This approximation is similar to the assumption of the CNDO-method made in order to maintain rotational invariance. To obtain an energy expression, containing a number of terms proportional to N2, (N is the number of occupied orbitals) the overlap of non-adjacent bond orbitals is neglected. At last a simple point-charge interaction is assumed to act between atoms lying far from each other. Thus the calculation of the energy involves the evaluation of a number of integrals proportional to the first power of N. Numerical results for H2, Li2 and LiH are given.

UR - http://www.scopus.com/inward/record.url?scp=0000858823&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0000858823&partnerID=8YFLogxK

U2 - 10.1007/BF03157503

DO - 10.1007/BF03157503

M3 - Article

AN - SCOPUS:0000858823

VL - 40

SP - 261

EP - 273

JO - Acta Physica Academiae Scientiarum Hungaricae

JF - Acta Physica Academiae Scientiarum Hungaricae

SN - 0001-6705

IS - 4

ER -