it is the Lanczos-subspace dimension.

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


<p><b><a name='TDExponentialMethod'></a>TDExponentialMethod</b>
<br/><i>Section</i>: Time-Dependent::Propagation
<br/><i>Type</i>: integer
<br/><i>Default</i>: taylor
<br/><br> Method used to numerically calculate the exponential of the Hamiltonian,
 a core part of the full algorithm used to approximate the evolution
 operator, specified through the variable <tt>TDPropagator</tt>.
 In the case of using the Magnus method, described b