ORAC is a program for running classical simulations of biomolecules. Simulations can be carried out in the NVE, NpT, NpH, and NVT thermodynamic ensembles. The integration of the equations of motion in any ensemble can be carried out with the r-RESPA multiple time step integrator and electrostatic interactions can be handled with the Smooth Particle Mesh Ewald method.
- Piero Procacci, Tom A. Darden, Emanuele Paci, Massimo Marchi "ORAC: A Molecular dynamics program to simulate complex molecular systems with realistic electrostatic interactions", Journal of Computational Chemistry 18 pp. 1848-1862 (1997)
- Simone Marsili, Giorgio Federico Signorini, Riccardo Chelli, Massimo Marchi and Piero Procacci "ORAC: A molecular dynamics simulation program to explore free energy surfaces in biomolecular systems at the atomistic level", Journal of Computational Chemistry 31 pp. 1106-1116 (2010)