Fig. 4: DFT calculations.
From: Photoinduced anisotropic lattice dynamic response and domain formation in thermoelectric SnSe
a DFT calculations of partial density of states for the structures relaxed with Te = 0 K (light lines) and Te = 6000 K (thick lines), showing that the 1.55 eV incident photons excite the electrons near the Fermi surface to high energy levels. b Photoinduced atomic displacements and relaxation that can be attributed to the transverse optical Ag phonon modes. The Sn-Se movement increases the intralayer lattice symmetry, while induces interlayer shear strain along c axis, which yields lattice distortions and formation of domains. c Projected weights of the atomic displacements into the four Ag modes of the low-temperature Pnma phase for different electron temperature Te. d Lattice distortion models corresponding to Ag phonon modes with different energy.
