For molecular dynamics simulations, it is possible to provide the initial velocity of each atom by the following keyword:
<MD.Init.Velocity 1 3000.000 0.0 0.0 2 -3000.000 0.0 0.0 MD.Init.Velocity>The example is for a system consisting of two atoms. If you have
 atoms, 
  then you have to provide
 atoms, 
  then you have to provide  rows in this specification.
  The 1st column is the same sequential number to specify atom as in the
  specification of the keyword 
  'Atoms.SpeciesAndCoordinates'.
  The 2nd, 3rd, and 4th columns are
 rows in this specification.
  The 1st column is the same sequential number to specify atom as in the
  specification of the keyword 
  'Atoms.SpeciesAndCoordinates'.
  The 2nd, 3rd, and 4th columns are  -,
-,  -, and
-, and  -components of the velocity 
  of each atom, respectively. The unit of the velocity is m/s. 
  The keyword 'MD.Init.Velocity'
  is compatible with the keyword 'MD.Fixed.XYZ'.
-components of the velocity 
  of each atom, respectively. The unit of the velocity is m/s. 
  The keyword 'MD.Init.Velocity'
  is compatible with the keyword 'MD.Fixed.XYZ'.