Hg2(SeO3)(SO4): the first sulfate selenite with large birefringence explored from d10 transition metal compounds

Hg 2 (SeO 3 )(SO 4 ), explored in the d 10 TM–Se( iv )–SO 4 system, features the first metal sulfate selenite with a large birefringence of up to 0.133 and 0.126 at 532 and 1064 nm, respectively.