Sr3 (Sr0.11 Ho1.89) (B O3)2 (Cu O2)3

B₂Cu₃Ho_1.89O₁₂Sr_3.11

Akiyoshi, M.Matsui, Y.Sato, A.Kopnin, E.M.Takayama-Muromachi, E.

Physica C (Amsterdam) (2003) 391, 245-250

a=3.8477Å   b=3.8477Å   c=17.7505Å

α=90°   β=90°   γ=90°