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;
}
}
}
