Molecule Types Asymmetric Tops | <Prev Next> |

If the parent molecule has nNuclei non zero, then
each state will have nNuclei
of the items listed below (TAsymmetricTopNucleus). The following
coupling scheme is normally used:

## Settings

Note that these two should be set at the molecule level, but are
in fact implemented at the state level, with any change in these
two properties copied to all the states in the molecule.

## Parameters

F_{1}
= J_{1 + }I_{1; }F_{2} = F_{1 + }I_{2}; ... F = F_{n-1} + I_{n
}

though an alternative scheme must be used for equivalent nuclei,
as described under the AsNext
setting.Note that only nuclei not explicitly simulated with nucleus
objects should be included in calculating the statistical
weights (eeWt and so
on). If all equivalent nuclei have been explicitly included,
then the statistical weights should be calculated as if there
were an additional pair of equivalent spin zero nuclei, which
will mean some mean weighs will be zero. A simple check for
correct operation is to compare the rotational structure with
and without the nuclei explicitly included, with the weights
calculated in the latter case including all nuclei. If the
linewidth is set somewhat larger than the width of the hyperfine
structure the spectra should appear identical.

For interactions between nuclei see Nuclear Spin - Nuclear Spin Coupling

Note that where *x*, *y* and *z* axes are
referred to below, the mapping to *a*, *b* and *c*
axes is determined by the representation - see Symmetry and Axis Systems so that, for
example, CHIzz corresponds to χ_{aa} in a I*r*
representation but χ_{cc} in a III*r*
representation.