=time_step><li>                 <span style="display:inline-block;background:#EEEEEE;width:400px">               <b>time_step</b>  </span>  
<br><br>
<i>Optional</i><br>
Default: 1.0<br><br>
Time step for real-time dynamics in atomic units.</li><br>
<hr>
<a name=vel_projectile><li>                 <span style="display:inline-block;background:#EEEEEE;width:400px">               <b>vel_projectile</b>  </span>  
<br><br>
<i>Optional</i><br>
Default: (0.0, 0.0, 1.0)<br><br>
Projectile initial velocity. Used for