DOI: 10.1098/rspa.1951.0048. The molecular orbital theory of chemical valency VIII. A method of calculating ionization potentials

The molecular orbital theory of chemical valency VIII. A method of calculating ionization potentials

10.1098/rspa.1951.0048

Crossref journal-article

The Royal Society

Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences (175)

Abstract

An analysis of the ‘linear combination of atomic orbitals’ approximation using the accurate molecular orbital equations shows that it does not lead to equations of the form usually assumed in the semi-empirical molecular orbital method. A new semi-empirical method is proposed, therefore, in terms of equivalent orbitals. The equations obtained, which do have the usual form, are applicable to a large class of molecules and do not involve the approximations that were thought necessary. In this method the ionization potentials are calculated by treating certain integrals as semi-empirical parameters. The value of these parameters is discussed in terms of the localization of equivalent orbitals and some approximate rules are suggested. As an illustration the ionization potentials of the paraffin series are considered and good agreement between the observed and calculated values is found.

Bibliography

The molecular orbital theory of chemical valency VIII. A method of calculating ionization potentials. (1951). Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 205(1083), 541â552.

Authors 0

None

References 13 Referenced 438

{'key': 'p_1', 'first-page': '336', 'article-title': 'Proc. Roy', 'volume': '202', 'author': 'Hall G. G.', 'year': '1950', 'journal-title': 'Soc. A'} / Soc. A / Proc. Roy by Hall G. G. (1950)
{'key': 'p_2', 'first-page': '155', 'article-title': 'Proc. Roy', 'volume': '202', 'author': 'Hall G. G.', 'year': '1950', 'journal-title': 'Soc. A'} / Soc. A / Proc. Roy by Hall G. G. (1950)
{'key': 'p_3', 'first-page': '357', 'article-title': 'Proc. Roy', 'volume': '205', 'author': 'Hall G. G.', 'year': '1951', 'journal-title': 'Soc. A'} / Soc. A / Proc. Roy by Hall G. G. (1951)
{'key': 'p_4', 'first-page': '105', 'article-title': 'J', 'volume': '16', 'author': 'Honig R. E.', 'year': '1948', 'journal-title': 'Chem. Phys.'} / Chem. Phys. / J by Honig R. E. (1948)
{'key': 'p_5', 'first-page': '204', 'article-title': 'Z', 'volume': '70', 'author': 'Hiickel E.', 'year': '1931', 'journal-title': 'Phys.'} / Phys. / Z by Hiickel E. (1931)
10.1039/tf9292500668
{'key': 'p_7', 'first-page': '280', 'article-title': 'Proc. Roy', 'volume': '158', 'author': 'Lennard-Jones Sir J. E.', 'year': '1937', 'journal-title': 'Soc. A'} / Soc. A / Proc. Roy by Lennard-Jones Sir J. E. (1937)
{'key': 'p_8', 'first-page': '1', 'article-title': 'Proc. Roy', 'volume': '198', 'author': 'Lennard-Jones Sir J. E.', 'year': '1949', 'journal-title': 'Soc. A'} / Soc. A / Proc. Roy by Lennard-Jones Sir J. E. (1949)
{'key': 'p_9', 'first-page': '166', 'article-title': 'Proc. Roy', 'volume': '202', 'author': 'Lennard-Jones Sir J. E.', 'year': '1950', 'journal-title': 'Soc. A'} / Soc. A / Proc. Roy by Lennard-Jones Sir J. E. (1950)
{'key': 'p_10', 'first-page': '510', 'article-title': 'Proc. Roy', 'volume': '196', 'author': 'Moffitt W.', 'year': '1949', 'journal-title': 'Soc. A'} / Soc. A / Proc. Roy by Moffitt W. (1949)
Mulliken R. S. 1935 a J . Chem. Phys. 3 375 (10.1063/1.1749683)
{'key': 'p_12', 'first-page': '517', 'article-title': '6 J', 'volume': '3', 'author': 'Mulliken R. S.', 'year': '1935', 'journal-title': 'Chem. Phys.'} / Chem. Phys. / 6 J by Mulliken R. S. (1935)
10.1051/jcp/1949460497

Dates

Type	When
Created	18 years, 8 months ago (Dec. 18, 2006, 5:49 p.m.)
Deposited	4 years, 6 months ago (Feb. 20, 2021, 2:09 p.m.)
Indexed	2 weeks, 1 day ago (Aug. 6, 2025, 8:23 a.m.)
Issued	74 years, 5 months ago (March 7, 1951)
Published	74 years, 5 months ago (March 7, 1951)
Published Online	28 years, 7 months ago (Jan. 1, 1997)
Published Print	74 years, 5 months ago (March 7, 1951)

Funders 0

None

BibTeX

@article{1951, volume={205}, ISSN={2053-9169}, url={http://dx.doi.org/10.1098/rspa.1951.0048}, DOI={10.1098/rspa.1951.0048}, number={1083}, journal={Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences}, publisher={The Royal Society}, year={1951}, month=mar, pages={541–552} }

JSON

{
  "indexed": {
    "date-parts": [
      [
        2025,
        8,
        6
      ]
    ],
    "date-time": "2025-08-06T12:23:07Z",
    "timestamp": 1754482987414
  },
  "reference-count": 13,
  "publisher": "The Royal Society",
  "issue": "1083",
  "license": [
    {
      "start": {
        "date-parts": [
          [
            1951,
            3,
            7
          ]
        ],
        "date-time": "1951-03-07T00:00:00Z",
        "timestamp": -594000000000
      },
      "content-version": "tdm",
      "delay-in-days": 0,
      "URL": "https://royalsociety.org/journals/ethics-policies/data-sharing-mining/"
    }
  ],
  "content-domain": {
    "domain": [],
    "crossmark-restriction": false
  },
  "published-print": {
    "date-parts": [
      [
        1951,
        3,
        7
      ]
    ]
  },
  "abstract": "<jats:p>An analysis of the \u2018linear combination of atomic orbitals\u2019 approximation using the accurate molecular orbital equations shows that it does not lead to equations of the form usually assumed in the semi-empirical molecular orbital method. A new semi-empirical method is proposed, therefore, in terms of equivalent orbitals. The equations obtained, which do have the usual form, are applicable to a large class of molecules and do not involve the approximations that were thought necessary. In this method the ionization potentials are calculated by treating certain integrals as semi-empirical parameters. The value of these parameters is discussed in terms of the localization of equivalent orbitals and some approximate rules are suggested. As an illustration the ionization potentials of the paraffin series are considered and good agreement between the observed and calculated values is found.</jats:p>",
  "DOI": "10.1098/rspa.1951.0048",
  "type": "journal-article",
  "created": {
    "date-parts": [
      [
        2006,
        12,
        18
      ]
    ],
    "date-time": "2006-12-18T22:49:02Z",
    "timestamp": 1166482142000
  },
  "page": "541-552",
  "source": "Crossref",
  "is-referenced-by-count": 438,
  "title": "The molecular orbital theory of chemical valency VIII. A method of calculating ionization potentials",
  "prefix": "10.1098",
  "volume": "205",
  "member": "175",
  "published-online": {
    "date-parts": [
      [
        1997,
        1
      ]
    ]
  },
  "reference": [
    {
      "key": "p_1",
      "first-page": "336",
      "article-title": "Proc. Roy",
      "volume": "202",
      "author": "Hall G. G.",
      "year": "1950",
      "journal-title": "Soc. A"
    },
    {
      "key": "p_2",
      "first-page": "155",
      "article-title": "Proc. Roy",
      "volume": "202",
      "author": "Hall G. G.",
      "year": "1950",
      "journal-title": "Soc. A"
    },
    {
      "key": "p_3",
      "first-page": "357",
      "article-title": "Proc. Roy",
      "volume": "205",
      "author": "Hall G. G.",
      "year": "1951",
      "journal-title": "Soc. A"
    },
    {
      "key": "p_4",
      "first-page": "105",
      "article-title": "J",
      "volume": "16",
      "author": "Honig R. E.",
      "year": "1948",
      "journal-title": "Chem. Phys."
    },
    {
      "key": "p_5",
      "first-page": "204",
      "article-title": "Z",
      "volume": "70",
      "author": "Hiickel E.",
      "year": "1931",
      "journal-title": "Phys."
    },
    {
      "key": "p_6",
      "doi-asserted-by": "publisher",
      "DOI": "10.1039/tf9292500668"
    },
    {
      "key": "p_7",
      "first-page": "280",
      "article-title": "Proc. Roy",
      "volume": "158",
      "author": "Lennard-Jones Sir J. E.",
      "year": "1937",
      "journal-title": "Soc. A"
    },
    {
      "key": "p_8",
      "first-page": "1",
      "article-title": "Proc. Roy",
      "volume": "198",
      "author": "Lennard-Jones Sir J. E.",
      "year": "1949",
      "journal-title": "Soc. A"
    },
    {
      "key": "p_9",
      "first-page": "166",
      "article-title": "Proc. Roy",
      "volume": "202",
      "author": "Lennard-Jones Sir J. E.",
      "year": "1950",
      "journal-title": "Soc. A"
    },
    {
      "key": "p_10",
      "first-page": "510",
      "article-title": "Proc. Roy",
      "volume": "196",
      "author": "Moffitt W.",
      "year": "1949",
      "journal-title": "Soc. A"
    },
    {
      "key": "p_11",
      "doi-asserted-by": "crossref",
      "unstructured": "Mulliken R. S. 1935 a J . Chem. Phys. 3 375",
      "DOI": "10.1063/1.1749683"
    },
    {
      "key": "p_12",
      "first-page": "517",
      "article-title": "6 J",
      "volume": "3",
      "author": "Mulliken R. S.",
      "year": "1935",
      "journal-title": "Chem. Phys."
    },
    {
      "key": "p_13",
      "doi-asserted-by": "publisher",
      "DOI": "10.1051/jcp/1949460497"
    }
  ],
  "container-title": "Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences",
  "original-title": [],
  "language": "en",
  "link": [
    {
      "URL": "https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1951.0048",
      "content-type": "application/pdf",
      "content-version": "vor",
      "intended-application": "text-mining"
    },
    {
      "URL": "https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1951.0048",
      "content-type": "unspecified",
      "content-version": "vor",
      "intended-application": "similarity-checking"
    }
  ],
  "deposited": {
    "date-parts": [
      [
        2021,
        2,
        20
      ]
    ],
    "date-time": "2021-02-20T19:09:57Z",
    "timestamp": 1613848197000
  },
  "score": 1,
  "resource": {
    "primary": {
      "URL": "https://royalsocietypublishing.org/doi/10.1098/rspa.1951.0048"
    }
  },
  "subtitle": [],
  "short-title": [],
  "issued": {
    "date-parts": [
      [
        1951,
        3,
        7
      ]
    ]
  },
  "references-count": 13,
  "journal-issue": {
    "issue": "1083",
    "published-print": {
      "date-parts": [
        [
          1951,
          3,
          7
        ]
      ]
    }
  },
  "alternative-id": [
    "10.1098/rspa.1951.0048"
  ],
  "URL": "http://dx.doi.org/10.1098/rspa.1951.0048",
  "relation": {},
  "ISSN": [
    "0080-4630",
    "2053-9169"
  ],
  "subject": [],
  "container-title-short": "Proc. R. Soc. Lond. A",
  "published": {
    "date-parts": [
      [
        1951,
        3,
        7
      ]
    ]
  }
}