Abstract

The R-lines of ruby are red-shifted linearly with hydrostatic pressure, with no quadratic effect, to 200 kbars.¹ The shift has been attributed, from crystal field analyses, to delocalization of the d-orbitals resulting in changes in the Racah parameters B and C.^2,3 From the adiabatic potential theory of pressure effects the linear shift of the R-lines is attributed to differences between the effects of pressure on the zero point energies of the excited and ground electronic states, primarily due to difference in anharmonicities of the two states; a quadratic shift arises from differences in the change in equilibrium energies with pressure, due to differences in coupling and/or force constants for the two states.

© 1984 Optical Society of America