int main(int numberOfArguments, char **argumentList) { //omp_set_num_threads(8); // initialize OpenMP //DEFAULT PARAMETERS: int numberOfUnitCells = 10; double initialTemperature = UnitConverter::temperatureFromSI(300.0); // measured in Kelvin double latticeConstant = UnitConverter::lengthFromAngstroms(5.26); // measured in angstroms double dt = UnitConverter::timeFromSI(1e-15); // measured in seconds // USER DEFINED PARAMETERS: if(numberOfArguments > 1) numberOfUnitCells = atoi(argumentList[1]); if(numberOfArguments > 2) initialTemperature = UnitConverter::temperatureFromSI(atof(argumentList[2])); if(numberOfArguments > 3) latticeConstant = UnitConverter::lengthFromAngstroms(atof(argumentList[3])); if(numberOfArguments > 4) dt = UnitConverter::timeFromSI(atof(argumentList[4])); // PRINT DIMENSION SCALING FACTORS: cout << "One unit of length is " << UnitConverter::lengthToSI(1.0) << " meters" << endl; cout << "One unit of velocity is " << UnitConverter::velocityToSI(1.0) << " meters/second" << endl; cout << "One unit of time is " << UnitConverter::timeToSI(1.0) << " seconds" << endl; cout << "One unit of mass is " << UnitConverter::massToSI(1.0) << " kg" << endl; cout << "One unit of temperature is " << UnitConverter::temperatureToSI(1.0) << " K" << endl; // CREATE AND INITIALIZE THE LATTICE: System system; system.createFCCLattice(numberOfUnitCells, latticeConstant, initialTemperature); double sigma = UnitConverter::lengthFromAngstroms(3.405); double epsilon = UnitConverter::temperatureFromSI(119.8); system.setPotential(new LennardJones(sigma, epsilon)); system.potential()->rCut = 2.5*sigma; system.potential()->rShell = 0.3*sigma; system.setIntegrator(new VelocityVerlet()); system.setThermostat(new Thermostat(UnitConverter::timeFromSI(1e-13), UnitConverter::temperatureFromSI(300.0))); system.removeTotalMomentum(); system.thermostat()->setOff(); int numberOfTimesteps = 2000; StatisticsSampler statisticsSampler; IO movie, data; movie.open("movie.xyz", 1); data.open("data.txt", 0); movie.saveState(&system); cout << "Timestep Time Temperature KineticEnergy PotentialEnergy" << "TotalEnergy DiffusionK Pressure Momentum" << endl; for(int timestep=0; timestep<numberOfTimesteps; timestep++) { system.step(dt); statisticsSampler.sample(system); data.saveStatistcalData(&system, &statisticsSampler); if( !(timestep % 100) ) { cout << system.steps() << " " << UnitConverter::timeToSI(system.time()) << " " << UnitConverter::temperatureToSI(statisticsSampler.temperature()) << " " << statisticsSampler.kineticEnergy() << " " << statisticsSampler.potentialEnergy() << " " << statisticsSampler.totalEnergy()<< " " << statisticsSampler.diffusionConstant()<< " " << UnitConverter::pressureToSI(statisticsSampler.pressure())<< " " << statisticsSampler.momentum() << endl; movie.saveState(&system); } } movie.close(1); data.close(0); return 0; }
int main(int numberOfArguments, char **argumentList) { clock_t executionTimeStart, executionTimeFinish; executionTimeStart = clock(); int numberOfUnitCells = 5; double initialTemperature = UnitConverter::temperatureFromSI(2000.0); // measured in Kelvin double latticeConstant = UnitConverter::lengthFromAngstroms(5.26); // measured in angstroms double dt = UnitConverter::timeFromSI(5e-15); // Measured in seconds int integratorNumber = 2; //initially set to Velocity Verlet, 1 is Euler-Cromer int numberOfTimesteps = 1000; // If a first argument is provided, it is the number of unit cells if(numberOfArguments > 1) numberOfUnitCells = atoi(argumentList[1]); // If a second argument is provided, it is the initial temperature (measured in MD units) if(numberOfArguments > 2) initialTemperature = atof(argumentList[2]); // If a third argument is provided, it is the lattice constant determining the density (measured in MD units) if(numberOfArguments > 3) latticeConstant = atof(argumentList[3]); // If a fourth argument is provided, it is the time step length dt (measured in MD units) if(numberOfArguments > 4) dt = atof(argumentList[4]); // If a fifth argument is provided, it is the integrator number if(numberOfArguments > 5) integratorNumber = atoi(argumentList[5]); // If a sixth argument is provided, it is the number of timesteps if(numberOfArguments > 6) numberOfTimesteps = atoi(argumentList[6]); /* // Possible to print the MD units used in the simulation cout << "One unit of length is " << UnitConverter::lengthToSI(1.0) << " meters" << endl; cout << "One unit of velocity is " << UnitConverter::velocityToSI(1.0) << " meters/second" << endl; cout << "One unit of time is " << UnitConverter::timeToSI(1.0) << " seconds" << endl; cout << "One unit of mass is " << UnitConverter::massToSI(1.0) << " kg" << endl; cout << "One unit of temperature is " << UnitConverter::temperatureToSI(1.0) << " K" << endl; */ System system; system.createFCCLattice(numberOfUnitCells, latticeConstant, initialTemperature); system.setPotential(new LennardJones(3.405, 1.0)); if(integratorNumber == 1) system.setIntegrator(new EulerCromer()); else if(integratorNumber == 2) system.setIntegrator(new VelocityVerlet()); system.removeTotalMomentum(); StatisticsSampler statisticsSampler; IO statisticsFile; // To write statistics to file for plotting IO movie; // To write the state to file to look at in Ovito if(numberOfArguments > 5){ // making unique filenames for plotting with python string filenameStatistics = "run_plot_python_output/statistics_file_NrOfCells" + to_string(numberOfUnitCells) + "_T" + to_string(int(initialTemperature*1000)) + "_b" + to_string(int(latticeConstant*1000)) + "_dt" + to_string(int(dt*10000)) + "_int" + to_string(integratorNumber) + ".txt"; statisticsFile.open(filenameStatistics.c_str()); string filenameMovie = "run_plot_python_output/movie_NrOfCells" + to_string(numberOfUnitCells) + "_T" + to_string(int(initialTemperature*1000)) + "_b" + to_string(int(latticeConstant*1000)) + "_dt" + to_string(int(dt*10000)) + "_int" + to_string(integratorNumber) + ".xyz"; movie.open(filenameMovie.c_str()); } else{ statisticsFile.open("statistics_file.txt"); movie.open("movie.xyz"); } cout << "Timestep Time Temperature KineticEnergy PotentialEnergy TotalEnergy DiffusionConstant MeanSquareDisplacement" << endl; for(int timestep=0; timestep<numberOfTimesteps; timestep++) { //movie.saveState(&system); //including also the starting position in the movie, uncomment to write to movie file system.step(dt); //moving the particle one step statisticsSampler.sample(system); statisticsFile.saveStatistics(&system, &statisticsSampler, 0); //output done here if( !(timestep % 100) ) { // Print the timestep every 100 timesteps cout << system.steps() << " " << system.time() << " " << statisticsSampler.temperature() << " " << statisticsSampler.kineticEnergy() << " " << statisticsSampler.potentialEnergy() << " " << statisticsSampler.totalEnergy() << " " << statisticsSampler.diffusionConstant() << " " << statisticsSampler.meanSquareDisplacement() << endl; } } movie.close(); executionTimeFinish = clock(); double totalExecutionTime = (( executionTimeFinish - executionTimeStart )/double(CLOCKS_PER_SEC )); cout << "Execution time: " << totalExecutionTime << endl; statisticsFile.saveStatistics(&system, &statisticsSampler, totalExecutionTime); statisticsFile.close(); return 0; }