The sample with a nominal composition of Ba31Y23Si46O157.5 contained the unknown phase referred to as Phase B which was at first indexed to a primitive tetragonal lattice (a = 16.476, c = 9.041 Å) using TOPAS Academic V7. Similar to phase A, the initial models were developed using both charge-flipping applied to the powder diffraction data and direct methods using CRED data. The outcomes from both methods converged on the space group P43212 with two 8b silicon, one 8b barium, one 4a yttrium, and one 8a mixed barium/yttrium (0.5:0.5) atomic sites. Additionally, the model was populated with seven 8b oxygen sites which coordinate silica atoms forming disilicate groups to result in a charge balanced formula Ba3Y2Si4O14. However, after refinement of the structural model against powder diffraction data, it lacked the necessary coordination for heavy atoms and the fit to experimental data required improvement. The higher symmetry model is shown in Figure for reference (atomic coordinates are listed in Table ). We have attempted to lower the symmetry to orthorhombic P212121 space group and to split the disilicate groups which did not resolve the mentioned problems. The diffraction patterns for selected models and statistics from the Rietveld refinements are shown in Figure and Table .