class="optiondescr">
<p>
If a number is given in this field, it specifies the orientational distribution of the supporting biomacromolecule in the sample. If not given or set to zero, the distribution is isotropic, i.e. all orientations occur with the same probability.
</p>

<p>
If a number is given, the orientational distribution is non-isotropic and computed according to the formula P(&beta;) = exp(-U(&beta;)) with U(&beta;) = -&lambda;(3 cos<sup>2</sup>&beta; - 1)/2, where &beta; is the angle between the