Rhombohedral (or trigonal) lattice has one lattice point at the each corner of the unit cell. It has unit cell vectors a=b=c and interaxial angles α=β=γ≠90°.
Generalic, Eni. "Rhombohedral lattice." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. 1 Apr. 2025. <https://glossary.periodni.com>.
Glossary
Periodic Table