Topological study of refractive indices, atomic charges, polar and axial vectors of second rank and optical rotation in α-HgS (cinnabar) at 296 K

The magnitude and sense of optical rotation are determined from the point charge model in a nonpolar, chiral, covalently bonded and semiconducting α-HgS (cinnabar) crystal. Atomic charges of Hg and S are variables in the iteration of topological equivalence between the inverted ratios of the second electric moments and the corresponding optical refractive indices of the α-HgS crystal. Vector cross products of the wave vector in the propagation direction of light and the second electric moments in the other two semi-axis directions of the quadric specify the handedness of axial vectors of second rank and the refractive indices comprise the magnitudes of them. The calculated axial vectors contain information of optical rotation and the handedness of the dominant component of them reveals the sense of rotational character of the crystal. They are converted to principal gyration tensor components and the magnitude and sense of rotation are computed in the direction of optic axis of the quadric. The sense of optical rotation is opposite to the sense of the helical arrangement of the atoms. The magnitude and sense of optical rotation solely arises from the asymmetric distribution of point charges and SCIREA Journal of Chemistry http://www.scirea.org/journal/Chemistry February 12, 2022 Volume 7, Issue 1, February 2022 https://doi.org/10.54647/chemistry15252