Two Hitherto Unknown Lithium Holmium(III) Ortho-Thiophosphates(V): Li9Ho2[PS4]5 and Li15Ho7[PS4]12

The two hitherto unknown lithium holmium(III) ortho-thiophosphates(V) Li9Ho2[PS4](5) and Li15Ho7[PS4](12) crystallize in the monoclinic space group C2/c with the lattice parameters a=1489.43(9) pm, b=979.84(6) pm, c=2051.68(12) pm, beta=96.221(3)degrees for Li9Ho2[PS4](5) (Z=4) and a=2826.73(16) pm, b=1003.25(6) pm, c=3361.46(19) pm, beta=113.992(3)degrees for Li15Ho7[PS4](12) (Z=5). While Li9Ho2[PS4](5) extends the Li9RE2[PS4](5) series, Li15Ho7[PS4](12) can be regarded as a cation-distribution variant of the Li6RE3[PS4](5) series (Z=12). Both structures feature characteristic [HoS8](13-) polyhedra (d(Ho3+-S2-)=275-314 pm) and [PS4](3-) tetrahedra (d(P5+-S2-)=202-207 pm), but Li15Ho7[PS4](12) exhibits one Ho3+ position, which is mixed occupied with Li+ and settles with C.N.=6+2. The coordination numbers of all other Li+ cations range from four to six in both new compounds with Li+-S2- distances from 238 to 317 pm.

Automated summary

Two previously unknown lithium holmium(III) ortho-thiophosphates(V), Li9Ho2[PS4](5) and Li15Ho7[PS4](12), crystallize in the monoclinic space group C2/c with distinct lattice parameters and structural features. Li15Ho7[PS4](12) stands out with a mixed occupied Ho3+ position in addition to characteristic polyhedra and tetrahedra.