If this variable is present, Octopus will assign random
velocities to the atoms following a Boltzmann distribution with
temperature given by RandomVelocityTemp (in degrees Kelvin).
The seed for the random number generator can be modified by setting
GSL_RNG_SEED environment variable.
If XYZVelocities, PDBVelocities, and XSFVelocities
are not present, Octopus will try to fetch the initial
atomic velocities from this block. If this block is not present, Octopus
will set the initial velocities to zero. The format of this block can be
illustrated by this example:
Octopus will try to read the starting velocities of the atoms from the XYZ file
specified by the variable XYZVelocities.
Note that you do not need to specify initial velocities if you are not going
to perform ion dynamics; if you are going to allow the ions to move but the velocities
are not specified, they are considered to be null.
Note: It is important for the velocities to maintain the ordering
in which the atoms were defined in the coordinates specifications.