From Intermolecular Poses to Thermodynamics Using Subdivided Spheres

Published

June 9, 2026

Author(s)

Isabel Vinterbladh, Jordan Bye, Robin Curtis, Harold Hatch, Sergei Grudinin, Mikael Lund

Abstract

Computing molecular thermodynamic properties is instrumental in multiple scientific disciplines, such as statistical physics, N-body simulations, and molecular docking. However, exact thermodynamic calculations are almost always not feasible. In this work, we introduce a versatile algorithm designed to rapidly compute the two-body partition function, its related thermodynamic properties, and the second virial coefficient for anisotropic nanoparticles and proteins under the rigid-body approximation. Our method involves constructing a quasi-regular grid in the 5D angular space between pairs of arbitrary objects and efficiently scanning the radial-angular space between the rigid molecules. Where available, we find excellent agreement with light and X-ray scattering experiments, as well as with Monte Carlo simulations. Our results suggest a correction to current coarse-grained protein force fields, and we further discover a new, counterintuitive effect of temperature on virial coefficients, caused by a population shift in angular space due to the dielectric response of water. Finally, the grid can serve as an interpolation table for N-body simulations, increasing their performance by orders of magnitude.

Citation

Journal of Physical Chemistry B

Volume

130

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.jpcb.6c01665

Local Download

Citation

Vinterbladh, I. , Bye, J. , Curtis, R. , Hatch, H. , Grudinin, S. and Lund, M. (2026), From Intermolecular Poses to Thermodynamics Using Subdivided Spheres, Journal of Physical Chemistry B, [online], https://doi.org/10.1021/acs.jpcb.6c01665, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=960364 (Accessed July 11, 2026)

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