Hello
Remember atoms are not hard spheres and that Allcock's definition of
secondary bonding as rij < (rvdwi + rvdwj) is an arbitrary
one based on a very intuitive idea of having these radii as the
boundaries of atoms. Such a definition was created to account for
intermolecular interactions in the solid state. In short I think you might
still call them halogen bonds but at the same time you should perform some
population analysis to assess the electron density between the interacting atoms
so you know whether or not you have a bond between them.
Some time ago we wrote a paper on the topic.
Barroso-Flores, J. et al J. Organomet. Chem. 689 (2004) 2096-2102
doi:10.1016/j.jorganchem.2004.03.035
Hope this helps
Joaquín
=======================================================
Joaquin
Barroso-Flores, Ph. D.
Centro Conjunto de Investigacion en Quimica
Sustentable
Instituto de Quimica
UNAM
-> http://joaquinbarroso.wordpress.com
joaquin.barroso''a''gmail.com