Hückel molecular orbital theory

{
  "id": "MLC-T-CHM-005411",
  "term": "Hückel molecular orbital theory",
  "field": "Chemistry",
  "definition": "The simplest molecular orbital theory of pi-conjugated systems, in which the pi orbitals are linear combinations of atomic p orbitals on the conjugated atoms. It treats the sigma framework as fixed, ignores electron repulsion, sets every overlap integral between different atoms to zero, and keeps a resonance integral beta only for bonded neighbors. Solving the secular determinant gives orbital energies of the form alpha plus x times beta, from which delocalization energies and the 4n plus 2 rule follow.",
  "synonyms": [
    "HMO theory"
  ],
  "subject": "Organic and Biomolecular Chemistry",
  "see_also": [
    "molecular orbital",
    "resonance"
  ],
  "references": [
    "PAC, 1999, 71, 1919. 'Glossary of terms used in theoretical organic chemistry' on page 1944 (https://doi.org/10.1351/pac199971101919)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/huckel-molecular-orbital-theory/"
}