Silver niobium trioxide, AgNbO3

The present structure determination of silver niobium trioxide at 291 K was performed on a twinned single crystal with a predominant presence [about 93 (1)%] of one twin domain. The sample contained traces of V (about 1 atomic %). This study confirms that the room-temperature phase of AgNbO3 is isostructural with the room-temperature phase of NaNbO3, i.e. it is a tilted perovskite. Structural deviation in AgNbO3 from centrosymmetry was not detected in this study and its structure was refined in Pbcm, though a previous study indicated ferroelectricity below 350 K, in contrast with NaNbO3.