Mean square displacement

Hi every one
1.I want to calculate diffusion coefficient using MD. Is there any key or option in GULP to calculate msd?
2.There is an option “absolute_coordinates” that I use it but I don’t find any thing in the output!!

  1. The diffusion coefficient isn’t something output by MD codes. You just analyse the trajectory of the MD to extract this.
  2. I guess you didn’t actually read the help text to see what absolute_coordinates does (see below):

Use : Specifies the absolute Cartesian coordinates of the atoms. Used for
: restarting MD calculations and determining properties, such as
: diffusion coefficients, where the migration across cell boundaries
: must be correctly tracked.

In other words, it’s an input to GULP when restarting your MD and appears in the restart file not the output.

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