pwtools.pydos.pyvacf

pwtools.pydos.pyvacf(vel, m=None, method=3)

Reference implementation for calculating the VACF of velocities in 3d array vel. This is slow. Use for debugging only. For production, use fvacf().

Parameters:

• vel (3d array, (nstep, natoms, 3)) – Atomic velocities.

• m (1d array (natoms,)) – Atomic masses.

• method (int) –

  1 : 3 loops

  2 : replace 1 inner loop

  3 : replace 2 inner loops

Returns:

c – VACF

Return type:

1d array (nstep,)