Ba₃Zn₄Si₄O₁₅: A Novel Centrosymmetric Silicate with Isolated SiO₄ and Si₂O₇ Units

A new silicate Ba 3 Zn 4 Si 4 O 15 (BZSO), was synthesized by the high‐temperature solution method in the open air, and the structure was determined using single‐crystal X‐ray diffraction data. The compound can be regarded as a derivative of α‐SiO 2 tetrahedral framework. The structural analysis indicates that it crystallizes in the centrosymmetric space group C 2/ c (No. 15) with lattice parameters a =19.3931(12) Å, b =5.1262(4) Å, c =16.3620(12) Å, β =115.7°, V =1465.5 Å 3 , Z =4 of a monoclinic crystal system composed of isolated Si 2 O 7 dimers, and SiO 4 , ZnO 4 tetrahedra. Experimental characterization demonstrates that it possesses birefringence of 0.013@546.1 nm. Besides, the first‐principles theoretical calculations were carried out to elucidate the relationship between the electronic structure and optical property.