These are the first examples known of strongly regular graphs with parameters $(540,187,58,68)$, arising from an imprimitive action of the group $\mathrm{PSU}(4,2)$, and discovered by Crnković, Rukavina and Švob (2018). We introduce the name "Trsat graphs" for these graphs in honour of the historic village where their university is located.
| Number of vertices: | $540$ |
| Diameter: | $2$ |
| Intersection array: | $\{187,128;1,68\}$ |
| Spectrum: | $187^1 7^{374} (-17)^{165}$ |
| Automorphism group: | $2 \times (\mathrm{PSU}(4,2):2)$ graph 1 |
| $2 \times \mathrm{PSU}(4,2)$ graph 2 | |
| Distance-transitive: | No |
| Primitive |