This graph is the unique rank-3 strongly regular graph with parameters $(351,126,45,45)$. This graph is the unique connected graph that is locally the $\mathrm{NO}_6^-(3)$ graph. This graph is the local graph of the $\mathrm{NO}_8^+(3)$ graph. This graph is a subgraph of the $\mathrm{Fi}_{22}$ graph.
| Number of vertices: | $351$ |
| Diameter: | $2$ |
| Intersection array: | $\{126,80;1,45\}$ |
| Spectrum: | $126^1 9^{168} (-9)^{182}$ |
| Automorphism group: | $\mathrm{PSO}(7,3) \cong \mathrm{O}(7,3):2$ |
| Distance-transitive: | Yes |
| Primitive |