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DOE OSTI · 3366993

Hierarchical Truncations for Many-Body Expansion Potentials

Westheimer, Bryce M. [Univ. of Colorado, Denver, CO (United States); Ames Laboratory (AMES), Ames, IA (United States); Iowa State Univ., Ames, IA (United States)]·Gordon, Mark S. [Ames Laboratory (AMES), Ames, IA (United States); Iowa State Univ., Ames, IA (United States)]·Guidez, Emilie B. [Univ. of Colorado, Denver, CO (United States)] (ORCID:0000000319610469)·Lin, Hai [Univ. of Colorado, Denver, CO (United States)] (ORCID:0000000235259122)
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Abstract

In this work, a new strategy to truncate high-order terms in the many-body expansion (MBE) is proposed. This new approach, which we call a hierarchical many-body expansion (HMBE), is based on a hierarchical partition of the system into multitier fragments and can in principle be applied to any large molecular system. Numerical tests on a series of (H 2 O) 64 structures are presented, demonstrating satisfactory relative energies between the clusters and binding energies of individual clusters compared with full-cluster calculations, with significantly fewer high-order terms computed than conventional MBE. The hierarchical truncation can be augmented by certain many-body terms for fragments at the interface between the partitions (called “Schengen terms”) to further improve accuracy. This work establishes the HMBE scheme as a promising framework to model very large systems (e.g., proteins), which are naturally built on a hierarchical structure.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYBinding energyChemical calculationsCluster chemistryFragmentationMolecular beam epitaxy

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Westheimer, Bryce M. [Univ. of Colorado, Denver, CO (United States); Ames Laboratory (AMES), Ames, IA (United States); Iowa State Univ., Ames, IA (United States)], Gordon, Mark S. [Ames Laboratory (AMES), Ames, IA (United States); Iowa State Univ., Ames, IA (United States)], Guidez, Emilie B. [Univ. of Colorado, Denver, CO (United States)] (ORCID:0000000319610469), Lin, Hai [Univ. of Colorado, Denver, CO (United States)] (ORCID:0000000235259122). 2026-05-20. Hierarchical Truncations for Many-Body Expansion Potentials. https://doi.org/10.1021/acs.jctc.6c00471

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