  A theory is presented which accounts for the dynamical generation of a
hybridization gap with nodes in the Kondo insulating materials $CeNiSn$ and
$CeRhSb$. We show that Hunds interactions acting on virtual $4f^2$
configurations of the cerium ion can act to dynamically select the shape of the
cerium ion by generating a Weiss field which couples to the shape of the ion.
In low symmetry crystals where the external crystal fields are negligible, this
process selects a nodal Kondo semimetal state as the lowest energy
configuration.
