This graph is the unique rank-3 strongly regular graph with parameters $(176,40,12,8)$. This graph is the complement of the $\mathrm{NU}_5(2)$ graph. The local graph of this graph is the $\mathrm{Sp}_4(3)$ graph, a.k.a the $\overline{\mathrm{NU}_4(2)}$ graph. This is the unique graph that is locally $\mathrm{GQ}(3,3)$.
| Number of vertices: | $176$ |
| Diameter: | $2$ |
| Intersection array: | $\{40,27;1,8\}$ |
| Spectrum: | $40^1 8^{55} (-4)^{120}$ |
| Automorphism group: | $\mathrm{P} \Gamma \mathrm{U}(5,2) \cong \mathrm{U}(5,2):2$ |
| Distance-transitive: | Yes |
| Primitive |