Lattice dynamics of amorphous silicon and spatially resolved computations of the thermal conductivity

Description of the sloppy-mode animations The supplemental video files show the sloppy modes identified for models DTW, R1, R2, and R3. The Rosset-10 model do not show any sloppy mode and its animation simply shows how delocalized the non-sloppy modes are. The sloppy modes in DTW are on a few amorphous SI atoms. The characteristics of the R1--R3 modes are summarized below. R1 70.36 cm⁻¹: The mode is localized primarily on a cluster of undercoordinated atoms surrounding a void. This cluster corresponds to a region with high δRᵢ values, and the atoms vibrate toward and away from the void. The mode also exhibits weaker localization in a second region containing another cluster of atoms with high δRᵢ values. R2 68.31 cm⁻¹: The mode is localized around several atoms with high δRᵢ values. Its most prominent localization occurs within a cluster surrounding undercoordinated atoms that form a void because of a missing linking atom. 69.13 cm⁻¹: This highly localized mode is concentrated on an undercoordinated atom with a high δRᵢ value and a strongly distorted bonding environment. The bonds connected to this atom form an approximately planar arrangement, and the dominant atomic motion is perpendicular to this plane. 80.99 cm⁻¹: The mode is localized primarily on an undercoordinated atom. As in the 69.13 cm⁻¹ mode, the atom vibrates predominantly perpendicular to the approximate plane defined by its bonds. R3 63.41 cm⁻¹: The mode is localized on a cluster of atoms surrounding an undercoordinated atom. The dominant motion is perpendicular to the approximate plane defined by the bonds connecting the undercoordinated atom to its neighbors. 70.45 cm⁻¹: The mode is localized around an undercoordinated atom with a highly distorted bonding environment. Consistent with several other modes, the dominant vibration is perpendicular to the approximate plane defined by the bonds between the atom and its neighbors. 85.95 cm⁻¹: The mode is localized around an overcoordinated atom bonded to an atom with a highly distorted local environment. The motion of the two most strongly participating atoms is dominated by bond stretching.