A question about the random number and its seed

Hi Haining,

Hi Ray,

I want rotate an atom randomly around the other using 'displace_atoms
rotate' command. So random numbers need to be generated to define a vector
(three real numbers ranging from -INF to INF) and an angle in degree with
the range from 0 to 360.

Well, the displace_atoms random keyword takes 4 arguments and the
rotate keyword takes 7. Either does not match your description above.
Please see: http://lammps.sandia.gov/doc/displace_atoms.html

But so far, after using 'variable equal random', it seems that all the
alignments are similar, not randomly generated.

The random function in variable takes 3 arguments. Please see:

What I am wondering is what is the proper way to generate random number in
LAMMPS using 'variable equal random' and how to set seeds? How seeds affect
random number generated?

This is a good start: http://en.wikipedia.org/wiki/Random_seed