[lammps-users] Variation on compute msd/ng: extracting the non-gaussian parameter for x, y, z components


I have been using the compute msd and msd/nongauss commands to compute mean square displacements as well as NGP(t) as specified in https://lammps.sandia.gov/doc/compute_msd_nongauss.html.

However, instead of computing NGP(t) with the full vector r(t), I would like to compute NGP with only x components of displacement vectors. I am hoping to compute <(x(0)-x(t))^4> rather than <(r(0)-r(t))^4>, as is currently output in the third vector component of the NGP command. Is there a way to do this via an addition compute step after invoking the displace/atom command?

Thank you,


I suspect you need to modify the source code for that and change what is computed and output accordingly.