Unveiling Ca ₉ N ₄ Te ₃ : A New Motif in Alkaline‐Earth Metal Chalcogenide Nitrides: A Combined Experimental and Computational Study

Green, moisture‐sensitive Ca 9 N 4 Te 3 was obtained from Ca/Na flux at 1173 K as a by‐product of reddish‐brown Ca 6 N 2 Te 3 and crystallizes in the trigonal space group R (No. 148, Z = 3). The crystal structure is characterized by layers of edge‐sharing trigonal prisms NCa 6 , face‐sharing with octahedra NCa 6 , which sandwich the layers of prisms. One telluride ion resides in the center of a cuboctahedron formed by 12 calcium cations, while a second crystallographic distinct telluride ion is surrounded by nine calcium ions and another telluride ion. According to electronic structure calculations, the title compound represents a semiconductor. The bonding is predominantly ionic in character. The average ICOBI value of 0.004 for Te(2)–Te(2) reflects that the attractive interaction between two Te(2) atoms is merely of van der Waals type.