“…They are coded in the CSD as bonded, and slight differences appear between the electron precise and hypercoordinated systems, except for the group 15 ones, for which no electron precise structures have been found. It is interesting to stress the presence of pristine group 13 MBz + molecular cations with hemispherical coordination, whose electronic structure is schematically depicted in 23 , where M is Ga, 242,243 In 244 or Tl, 245 all with similar penetration indices between 50 and 62%.…”