摘要：appeared in the Raman spectra except for the LO and TO lines because of the reduction of structure symmetry. However the frequencies and pressure dependences of the four Raman modes remain unchanged under different nonhydrostatic stresses. Appearance of new Raman modes under nonhydrostatic stress and the linear relationship of the differences of lattice constants under hydrostatic and nonhydrostatic stresses with differential stress can be used to indicate state of stress in high pressure experiments. The effect of nonhydrostatic stress on materials under high pressure is complicated and our calculation would help to understanding state of stress at high pressure experiments.
