<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Colorless block‐shaped crystals of the title compound are hydrothermally synthesized from mixtures of CdCl<sub>2</sub>, Na<sub>2</sub>CO<sub>3</sub>, and H<sub>2</sub>O (autoclave, 220 °C, 5 d, 80% yield).</p> </abstract>