In which of the following pairs, both the species are not isostructural?

Check structures using hybridization:${\text{NH}}_3,{\text{PH}}_3$: Both are $s{p}^3$ with $1$ lone pair (Pyramidal).${\text{XeF}}_4$: $s{p}^3{d}^2$ with $2$ lone pairs (Square planar). ${\text{XeO}}_4$: $s{p}^3$ with $0$ lone pairs (Tetrahedral). They are not isostructural.${\text{SiCl}}_4,{\text{PCl}}_4^{+}$: Both are $s{p}^3$ with $0$ lone pairs (Tetrahedral).Diamond and $\text{SiC}$: Both have $3$ D tetrahedral lattice arrangements.