public static void Main(string[] args)
{
//WriteData myData = new WriteData();
StaticVariables.myEnvironment = new CreateEnvironment();
StaticVariables.myEnvironment.PreCompute();
StaticVariables.myEnvironment.InitAtoms();
if (StaticVariables.currentPotential == StaticVariables.Potential.LennardJones)
{
LennardJones.calculateVerletRadius();
}
if (StaticVariables.currentPotential == StaticVariables.Potential.Buckingham)
{
Buckingham.calculateVerletRadius();
}
Console.WriteLine("Number of atoms = " + StaticVariables.myEnvironment.numAtoms);
float totalTime = 20000.0f * StaticVariables.MDTimestep;
Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
while (StaticVariables.currentTime < totalTime)
{
PhysicsEngine.VelocityVerlet();
PhysicsEngine.ReflectFromWalls();
PhysicsEngine.CalculateEnergy();
PairDistributionFunction.calculatePairDistribution();
StaticVariables.currentTime = StaticVariables.currentTime + StaticVariables.MDTimestep;
StaticVariables.iTime++;
//myData.WritePosition();
//Console.WriteLine("iTime = " + StaticVariables.iTime);
}
stopwatch.Stop();
//myData.WritePairDistribution();
Console.WriteLine("iTime = " + StaticVariables.iTime + " Current Time = " + StaticVariables.currentTime);
Console.WriteLine("Time elapsed: {0}", stopwatch.Elapsed);
Console.ReadLine();
}
public void PreCompute()
{
Atom.templateAtoms.Add(new Copper());
Atom.templateAtoms.Add(new Gold());
Atom.templateAtoms.Add(new Platinum());
// delete the template atoms from the list of m_AllAtoms in Atom.cs
for (int i = 0; i < Atom.templateAtoms.Count; i++)
{
Atom.AllAtoms.Clear();
}
if (StaticVariables.currentPotential == StaticVariables.Potential.LennardJones)
{
LennardJones.preCompute();
}
if (StaticVariables.currentPotential == StaticVariables.Potential.Buckingham)
{
Buckingham.preCompute();
}
}
public static void CalculateEnergy()
{
StaticVariables.potentialEnergy = 0.0f;
StaticVariables.kineticEnergy = 0.0f;
StaticVariables.currentTemperature = 0.0f;
for (int i = 0; i < Atom.AllAtoms.Count - 1; i++)
{
Atom firstAtom = Atom.AllAtoms[i];
// calculate kinetic energy of each atom
float velocitySqr = firstAtom.velocity[0] * firstAtom.velocity[0] + firstAtom.velocity[1] * firstAtom.velocity[1] + firstAtom.velocity[2] * firstAtom.velocity[2];
StaticVariables.kineticEnergy += 0.5f * firstAtom.massamu * StaticVariables.amuToKg * velocitySqr * StaticVariables.angstromsToMeters * StaticVariables.angstromsToMeters;
// calculate potential energy between each pair of atoms
if (StaticVariables.currentPotential == StaticVariables.Potential.LennardJones)
{
for (int j = 0; j < firstAtom.neighborList.Count; j++)
{
Atom secondAtom = firstAtom.neighborList[j];
StaticVariables.potentialEnergy += LennardJones.getPotential(firstAtom, secondAtom);
}
}
else if (StaticVariables.currentPotential == StaticVariables.Potential.Buckingham)
{
for (int j = 0; j < firstAtom.neighborList.Count; j++)
{
Atom secondAtom = firstAtom.neighborList[j];
StaticVariables.potentialEnergy += Buckingham.getPotential(firstAtom, secondAtom);
}
}
}
StaticVariables.currentTemperature = StaticVariables.kineticEnergy / 1.5f / (float)Atom.AllAtoms.Count / StaticVariables.kB;
calculateSqrtAlpha();
}
public static void VelocityVerlet()
{
// update the position of all atoms then initialize the acceleration to be updated
for (int i = 0; i < Atom.AllAtoms.Count; i++)
{
Atom currAtom = Atom.AllAtoms[i];
for (int idx = 0; idx < 3; idx++)
{
currAtom.position[idx] = currAtom.position[idx] + currAtom.velocity [idx] * StaticVariables.MDTimestep + 0.5f * StaticVariables.MDTimestepSqr * currAtom.accelerationNew [idx];
}
currAtom.accelerationOld = currAtom.accelerationNew;
currAtom.accelerationNew = new float[3] {
0.0f, 0.0f, 0.0f
};
}
if (StaticVariables.currentPotential == StaticVariables.Potential.LennardJones)
{
if (StaticVariables.iTime % StaticVariables.nVerlet == 0)
{
LennardJones.calculateNeighborList();
}
// update the acceleration of all atoms
for (int i = 0; i < Atom.AllAtoms.Count - 1; i++)
{
Atom firstAtom = Atom.AllAtoms[i];
for (int j = 0; j < firstAtom.neighborList.Count; j++)
{
Atom secondAtom = firstAtom.neighborList[j];
LennardJones.getForce(firstAtom, secondAtom);
}
}
}
else if (StaticVariables.currentPotential == StaticVariables.Potential.Buckingham)
{
if (StaticVariables.iTime % StaticVariables.nVerlet == 0)
{
Buckingham.calculateNeighborList();
}
// update the acceleration of all atoms
for (int i = 0; i < Atom.AllAtoms.Count - 1; i++)
{
Atom firstAtom = Atom.AllAtoms[i];
for (int j = 0; j < firstAtom.neighborList.Count; j++)
{
Atom secondAtom = firstAtom.neighborList[j];
Buckingham.getForce(firstAtom, secondAtom);
}
}
}
// update the velocity of all atoms
for (int i = 0; i < Atom.AllAtoms.Count; i++)
{
Atom currAtom = Atom.AllAtoms[i];
for (int idx = 0; idx < 3; idx++)
{
currAtom.velocity[idx] = currAtom.velocity[idx] + 0.5f * (currAtom.accelerationOld[idx] + currAtom.accelerationNew[idx]) * StaticVariables.MDTimestep;
currAtom.velocity[idx] = currAtom.velocity[idx] * StaticVariables.sqrtAlpha;
}
}
}
