A theory is presented which accounts for the dynamical generation of ahybridization 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 thecerium 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, thisprocess selects a nodal Kondo semimetal state as the lowest energyconfiguration.
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