Crystals. -The salt that precipitates from aqueous solutions of (NH4)2CO3 and H2SeO3 (1:2 molar ratio) at 25°C is characterized by NMR and Raman spectroscopy and found to be the monohydrate of hydrogen selenite, NH4HSeO3·H2O, and not the trihydrate of pyroselenite, (NH4)2Se2O5·3H2O, as suggested previously. -(NASLUZOVA*, O. I.; VINOGRADOVA, I. S.; LUNDIN, A. G.; ZHIDKOV, L. L.; Solid State