Article · Wikipedia archive · Last revised Jul 13, 2026

Orac (MD program)

In computer software, Orac is a classical molecular dynamics program, to simulate complex molecular systems at the atomistic level. In 1989–1990, the code was written originally by Massimo Marchi during his stay at International Business Machines (IBM), Kingston (USA). In 1995, the code was developed further at the Centre européen de calcul atomique et moléculaire (CECAM). It is written in the programming language Fortran. In 1997, it was released under a GNU General Public License (GPL). The latest release of Orac may be run in parallel using the standard Message Passing Interface (MPI) libraries, allowing replica exchange simulations, multiple walkers metadynamics simulations and multiple steered molecular dynamics nonequilibrium trajectories.

Last revised
Jul 13, 2026
Read time
≈ 1 min
Length
290 w
Citations
4
Source
Orac
Original authorsMassimo Marchi, Piero Procacci
DevelopersCEA, Saclay, Paris, FR; Florence University, IT
Release1990 (1990)
Stable release
5.4.1 / 2010 (2010)
Preview release
6.0 / 2016 (2016)
Written inFortran
Operating systemUnix, Linux
PlatformIA-32, x86-64, NUMA
Available inEnglish
TypeMolecular dynamics
LicenseGPL
Websitewww.chim.unifi.it/orac

In computer software, Orac is a classical molecular dynamics program, to simulate complex molecular systems at the atomistic level. In 1989–1990, the code was written originally by Massimo Marchi during his stay at International Business Machines (IBM), Kingston (USA). In 1995, the code was developed further at the Centre européen de calcul atomique et moléculaire (CECAM). It is written in the programming language Fortran. In 1997, it was released under a GNU General Public License (GPL).1 The latest release 2 of Orac may be run in parallel using the standard Message Passing Interface (MPI) libraries, allowing replica exchange simulations, multiple walkers metadynamics3 simulations and multiple steered molecular dynamics4 nonequilibrium trajectories.

See also

See also

References

References

  1. Procacci, P.; Darden, T.A.; Paci, E.; Marchi, M. (1997). "ORAC: A Molecular Dynamics Program to Simulate Complex Molecular Systems with Realistic Electrostatic Interactions". Journal of Computational Chemistry. 18 (15): 1848–1862. CiteSeerX 10.1.1.554.895. doi:10.1002/(SICI)1096-987X(19971130)18:15<1848::AID-JCC2>3.0.CO;2-O.
  2. Marsili, S.; Signorini, G.F.; Chelli, R.; Marchi, M.; Procacci, P. (2010). "ORAC: A molecular dynamics simulation program to explore free energy surfaces in biomolecular systems at the atomistic level". Journal of Computational Chemistry. 31 (5): 1106–1116. doi:10.1002/jcc.21388. PMID 19824035.
  3. Laio, A.; Gervasio, F. L. (2008). "Metadynamics: A method to simulate rare events and reconstruct the free energy in biophysics, chemistry and material science". Reports on Progress in Physics. 71 (12) 126601. Bibcode:2008RPPh...71l6601L. doi:10.1088/0034-4885/71/12/126601.
  4. Isralewitz, B.; Gao, M.; Schulten, K. (2001). "Steered molecular dynamics and mechanical functions of proteins". Current Opinion in Structural Biology. 11 (2): 224–230. doi:10.1016/S0959-440X(00)00194-9. PMID 11297932.
External links