There are examples with even more electrons around the central atom, such as IF7
(14 electrons), [TaF]-8 (16 electrons), and [ XeF8 ]-2 (18 electrons). There are rarely
more than 18 electrons (2 for S, 6 for P, and 10 for d orbitals) around a single atom in the
top half of the periodic table, and crowding of the outer atoms usually keeps the number
below this, even for the much heavier atoms with f orbitals energetically available.