First principles calculation of the nonhydrostatic effects on structure and Raman frequency of 3C-SiC.

For understanding the quantitative effect of nonhydrostatic stress on properties of material, the crystal structure and Raman spectra of 3C-SiC under hydrostatic and nonhydrostatic stress were calculated using a first-principles method. The results show that the lattice constants (a, b, and c) under nonhydrostatic stresses deviate those under hydrostatic stress. The differences of the lattice constants under hydrostatic stress from nonhydrostatic stresses with differential stress were fitted by linear equation.