Near Zero Area Compressibility in a Perovskite-Like Metal–Organic Frameworks [C(NH₂)₃][Cd(HCOO)₃]

Materials with zero area compressibility (ZAC) can keep their crystal uncompressed in two specific directions upon uniform compression. High-pressure angle-dispersive X-ray powder diffraction (ADXRD) experiments reveal a ZAC phenomenon in the ab-plane in crystal of a formate-based perovskite, [C(NH2)3][Cd(HCOO)3]. The ZAC behavior is ascribed to the unique rhombohedral [Cd(HCOO)3]− frameworks and confirmed by density functional theory (DFT) calculations. For the first time, a near ZAC single material is explicitly reported. This study opens up an exciting research field on pressure-resistant materials. We anticipate more ZAC materials to be discovered in the following explorations under the inspiration of this work.