The platinum-rich scandium silicide Sc₂Pt₉Si₃

Single crystals of Sc₂Pt₉Si₃ have been obtained from an arc-melted and inductively annealed sample of the starting composition Sc:4Pt:2Si. The Sc₂Pt₉Si₃ structure (Tb₂Pt₉Ge₃ type, space group C2/c) was refined from single crystal X-ray diffractometer data: a=1303.4(1), b=749.9(1), c=973.5(1), β=116.44(1) ^circle, wR2=0.0731, 1643 F² values and 67 variables. The structure contains three basic coordination polyhedra Sc rate at Pt₁₁, Si1 rate at Pt₈ and Si2 rate at Pt₈ which show a simple condensation pattern avoiding direct Sc-Si and Si-Si bonding.