# Unravelling the origin of intermolecular interactions using absolutely localized molecular orbitals.
> 絶対局在分子軌道を用いた分子間相互作用の起源解析


## Abstract

A new energy decomposition analysis (EDA) framework was developed to separate intermolecular interaction energies into physically meaningful components: frozen monomer density contributions, polarization-driven energy lowering, and charge-transfer effects. Polarization is treated in a fully self-consistent manner by constraining molecular orbital coefficients to a block-diagonal (absolutely localized) form, thereby preventing charge transfer during the SCF procedure. A perturbative approach applied to this optimized reference enables separation of forward and back-donation within the charge-transfer term. The method was applied to characterize covalency in water hydrogen bonding, synergic bonding in metal complexes, the interaction of molecular hydrogen (H2) with open metal centers in candidate hydrogen storage materials, and methane binding to rhenium complexes.

### Mechanism

Polarization and charge-transfer contributions are separated by constraining MO coefficients to a block-diagonal form in an SCF calculation; a perturbative step then distinguishes forward from back-donation within the charge-transfer term.

## Bibliographic

- **Authors**: Khaliullin RZ, Cobar EA, Lochan RC, Bell AT, Head-Gordon M
- **Journal**: J Phys Chem A
- **Year**: 2007 (2007-09-13)
- **PMID**: [17655284](https://pubmed.ncbi.nlm.nih.gov/17655284/)
- **DOI**: [10.1021/jp073685z](https://doi.org/10.1021/jp073685z)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 17655284. https://h2-papers.org/en/papers/17655284
> **Source**: PubMed PMID [17655284](https://pubmed.ncbi.nlm.nih.gov/17655284/)