This graph is the unique rank-3 strongly regular graph with parameters $(378,117,36,36)$. The local graph of this graph is the $\mathrm{NO}_6^+(3)$ graph. This graph is the local graph of the $\mathrm{NO}_8^-(3)$ graph.
| Number of vertices: | $378$ |
| Diameter: | $2$ |
| Intersection array: | $\{117,80;1,36\}$ |
| Spectrum: | $117^1 9^{182} (-9)^{195}$ |
| Automorphism group: | $\mathrm{PSO}(7,3) \cong \mathrm{O}_7(3):2$ |
| Distance-transitive: | Yes |
| Primitive |