THE NONEQUIVALENCE OF x-AXIS AND y-AXIS FOR RAMAN SPECTRA OF UNIAXIAL CRYSTALS
单轴晶体喇曼光谱的x轴和y轴的非等效性

In this paper, we show that in Raman spectrum of uniaxial crystals, for nonpolar mode and A(z) (or B(z)) mode, under any scattering geometry, x-axis and y-axis are always equivalent. For polar mode E(x) and E(y), in the tetragonal and hexagonal crystal systems, x-axis and y-axis are equivalent in most cases; but in the trigonal crystal system, they are equivalent only in a few cases.