Orac (MD program)

{{About|a molecular dynamics program|more meanings of the word Orac|ORAC (disambiguation){{!}}ORAC}}

{{Infobox software

| name = Orac

| logo =

| logo alt =

| logo caption =

| screenshot =

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| caption =

| author = Massimo Marchi, Piero Procacci

| developer = CEA, Saclay, Paris, FR; Florence University, IT

| released = {{Start date and age|1990}}

| latest release version = 5.4.1

| latest release date = {{Start date and age|2010}}

| latest preview version = 6.0

| latest preview date = {{Start date and age|2016}}

| programming language = Fortran

| operating system = Unix, Linux

| platform = IA-32, x86-64, NUMA

| size =

| language = English

| genre = Molecular dynamics

| license = GPL

| website = {{URL|www.chim.unifi.it/orac}}

| repo =

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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).

{{cite journal

|last1= Procacci |first1= P.

|last2= Darden |first2= T.A.

|last3= Paci |first3= E.

|last4= Marchi |first4= M.

|year= 1997

|title= ORAC: A Molecular Dynamics Program to Simulate Complex Molecular Systems with Realistic Electrostatic Interactions

|journal= Journal of Computational Chemistry

|volume= 18 |issue= 15 |pages= 1848–1862

|doi =10.1002/(SICI)1096-987X(19971130)18:15<1848::AID-JCC2>3.0.CO;2-O

|citeseerx= 10.1.1.554.895

}} The latest release

{{Cite journal

|last1= Marsili |first1= S.

|last2= Signorini |first2= G.F.

|last3= Chelli |first3= R.

|last4= Marchi |first4= M.

|last5= Procacci |first5= P.

|year= 2010

|title= ORAC: A molecular dynamics simulation program to explore free energy surfaces in biomolecular systems at the atomistic level

|journal= Journal of Computational Chemistry

|volume= 31 |issue= 5 |pages= 1106–1116

|doi =10.1002/jcc.21388

|pmid= 19824035

|doi-access=

}} of Orac may be run in parallel using the standard Message Passing Interface (MPI) libraries, allowing replica exchange simulations, multiple walkers metadynamics

{{Cite journal

|last1= Laio |first1= A.

|last2= Gervasio |first2= F. L.

|year= 2008

|title= Metadynamics: A method to simulate rare events and reconstruct the free energy in biophysics, chemistry and material science

|journal= Reports on Progress in Physics

|volume= 71 |issue= 12 |pages= 126601

|doi=10.1088/0034-4885/71/12/126601

|bibcode= 2008RPPh...71l6601L }} simulations and multiple steered molecular dynamics

{{Cite journal

|last1= Isralewitz |first1= B.

|last2= Gao |first2= M.

|last3= Schulten |first3= K.

|year= 2001

|title= Steered molecular dynamics and mechanical functions of proteins

|journal= Current Opinion in Structural Biology

|volume= 11 |issue= 2 |pages= 224–230

|doi= 10.1016/S0959-440X(00)00194-9

|pmid= 11297932

}} nonequilibrium trajectories.