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Updated: Jun 19, 2026

New Features in Visual Dynamics 3.0
Published on: August 9, 2024
ORAC: a molecular dynamics simulation program to explore free energy surfaces in biomolecular systems at the
Simone Marsili1, Giorgio Federico Signorini, Riccardo Chelli
1Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, I-50019 Sesto Fiorentino, Italy.
Abstract:
We present the new release of the ORAC engine (Procacci et al., Comput Chem 1997, 18, 1834), a FORTRAN suite to simulate complex biosystems at the atomistic level. The previous release of the ORAC code included multiple time steps integration, smooth particle mesh Ewald method, constant pressure and constant temperature simulations. The present release has been supplemented with the most advanced techniques for enhanced sampling in atomistic systems including replica exchange with solute tempering, metadynamics and steered molecular dynamics. All these computational technologies have been implemented for parallel architectures using the standard MPI communication protocol. ORAC is an open-source program distributed free of charge under the GNU general public license (GPL) at http://www.chim.unifi.it/orac.
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