newanalysis.diffusion.nonGaussianParameter

newanalysis.diffusion.nonGaussianParameter(xyz, n=2, maxlen=None)

This function takes as input a three-dimensional coordinate array of the molecular centers of mass of a whole unfolded trajectory [timestep, molecule, xyz] and calculates the non-Gaussian Parameter according to Rahman, A. Physical Review 136, A405–A411 (1964). n is the “moment” of the distribution and 2 per default. The non-Gaussian parameter describes the deviation of the time-dependent molecular displacement from theGaussian distribution and is zero for n>1 if the distribution of the displacements is actually Gaussian. The optional parameter maxlen can be set to limit the length of the resulting MSD. This can be useful when dealing with very long trajectories, e.g. maxlen=n/2.

Usage:

nonGaussianParameter = nonGaussianParameter(xyz)