Why does sulfur hexafluoride not follow the octet rule?

Sulfur hexafluoride ($S{F}_6$) does not follow the octet rule because it is a hypervalent compound. In $S{F}_6$, the central sulfur atom is bonded to six fluorine atoms, which requires the presence of 12 electrons in its valence shell—exceeding the eight-electron arrangement defined by the octet rule.1

While it was traditionally argued that this expansion of the octet was made possible by the availability of empty d orbitals in period-3 elements, modern quantum mechanical theories suggest that hypervalence is more accurately viewed as a steric or geometric phenomenon. The larger atomic radius of period-3 elements compared to those in period 2 allows a central atom to accommodate more surrounding atoms, rather than relying on d-orbital participation. Consequently, $S{F}_6$ adopts a regular octahedral arrangement to minimize electron pair repulsions, as predicted by VSEPR theory.12