if you have determined an
 optimal electronic time step (that we can call <i>dte</i>), it is
 recommended that you define your time step as:
<br><br>
 <tt>TDTimeStep</tt> = <i>dte</i> * <tt>TDIonicTimeScale</tt>
<br><br>
 so you will always use the optimal electronic time step.
<br><br>
 For more details see: <tt>http://arxiv.org/abs/0710.3321</tt>
<br><br>

</p><hr width='30%' align='left'/>


<p><b><a name='TDLanczosTol'></a>TDLanczosTol</b>
<br/><i>Section</i>: Time-Dependent::Propagation
<br/><i>Type</i