Sa. Kim et al., OPTICAL-ACTIVITY IN POTASSIUM TRIHYDROGEN DI(CIS-4-CYCLOHEXENE-1,2-DICARBOXYLATE) DIHYDRATE (POINT GROUP (4)OVER-BAR-2M), Zeitschrift fur Kristallographie, 208, 1993, pp. 219-222
Optical activity in crystal class 42mBAR was observed with simple expe
rimental methods for the first time in 1968 with AgGaS2 because, at a
certain wavelength, n(e) equals n0. The present study introduces a fur
ther example where this phenomenon can be observed. The title compound
has the refractive indices n(e) = n0 = 1.543(1) at 512 nm.