Crystal Structure of ?

Id2007870
Chemical name ?
a (Å)17.942(3)
b (Å)17.942(3)
c (Å)28.450(6)
α (°)90.00
β (°)90.00
γ (°)120.00
V (Å3)7931(3)
Space groupR -3 c :H
Temperature (K)293(2)