Complex sentence: In the xenon fluorides, all bonds are described with the 3-center 4-electron model and in PF 5 and SF 6, all bonds are described by an extended version of the 3-center 4-electron model (see below).
Split into simpler sentences: In the xenon fluorides, all bonds are described with the 3-center 4-electron model. Molecules without an s-orbital lone pair such as PF 5 and SF 6 are described by an extended version of the 3-center 4-electron model (see below).