Fragment Molecular Orbital Methods in Molecular Interactions

The fragment molecular orbital (FMO) method is a quantum‐chemical strategy that partitions large molecular systems into smaller, chemically meaningful fragments for tractable ab initio calculations. By computing the electronic structure of each fragment and their pairwise interactions, FMO delivers detailed inter‐fragment interaction energies, enabling decomposition of total binding energies into electrostatic, exchange–repulsion, charge‐transfer and dispersion components. This capability has revolutionised the quantitative analysis of ligand–receptor recognition, protein folding energetics, metalloprotein coordination and excitonic coupling in pigment–protein complexes. Rapid advances in computational protocols have extended FMO to thousands of residues or to ensemble averages derived from molecular dynamics, providing dynamic and statistical insights into complex biochemical assemblies. The method underpins improved scoring functions for drug discovery, large‐scale datasets for machine learning, and the rational design of small‐molecule inhibitors and allosteric modulators. By combining FMO with continuum solvation models, density‐functional tight‐binding or many‐body expansions, researchers now capture key contributions from solvent and higher‐order interactions, bridging the gap between rigorous quantum mechanics and practical applications in medicinal chemistry, enzymology and materials science.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Fragment Molecular Orbital Methods in Molecular Interactions publication trend

The graph below shows the total number of articles in fragment molecular orbital methods in molecular interactions across all publications each year (not limited to Nature Index journals).

Technical terms

Fragment Molecular Orbital (FMO) method: A quantum‐chemical technique that divides a large molecule into fragments to perform ab initio calculations on each fragment and their interactions.

Inter‐Fragment Interaction Energy (IFIE): The computed energy quantifying the pairwise interaction between two fragments, used to dissect total binding energies.

Pair Interaction Energy Decomposition Analysis (PIEDA): A procedure that breaks down IFIEs into electrostatic, exchange–repulsion, charge‐transfer and dispersion contributions.

Binding Free Energy: The thermodynamic quantity describing the affinity between two molecules, often estimated by combining quantum mechanical and solvation terms.

Many‐Body Expansion (MBE): A fragmentation approach that systematically includes contributions from single fragments, pairs, triples and higher orders to approximate total molecular energy.

References

1. Quantum chemical calculation dataset for representative protein folds by the fragment molecular orbital method. Scientific Data (2024).
2. Binding Free Energy Calculation Based on the Fragment Molecular Orbital Method and Its Application in Designing Novel SHP-2 Allosteric Inhibitors. International Journal of Molecular Sciences (2024).
3. A simple and consistent quantum‐chemical fragmentation scheme for proteins that includes two‐body contributions. Journal of Computational Chemistry (2023).
4. Rapid and accurate assessment of GPCR–ligand interactions Using the fragment molecular orbital‐based density‐functional tight‐binding method. Journal of Computational Chemistry (2017).
5. Towards a quantitative description of excitonic couplings in photosynthetic pigment–protein complexes: quantum chemistry driven multiscale approaches. Physical Chemistry Chemical Physics (2022).