e></div>
<div class="optiondescr">
This specifies which method is use to construct the Liouville matrix (i.e. the Hamiltonian and the relaxation superoperator). The two possible values are <code>'fast'</code> and <code>'general'</code>. The fast method is very fast, but limited to one electron spin with S=1/2 coupled to up to two nuclei and to orientational potentials with even L&le;4, zero M, even K &le;2, and real coefficients. On the other hand, the general method works for any spin system and any form o