Perturbative second-order optical susceptibility of bulk materials: a symmetry-enforced return to non-orthogonal localized basis sets

Angiolo Huaman, Luis Enrique Rosas-Hernandez, Salvador Barraza-Lopez

The second-order optical susceptibility of semiconductors $\ddot{I}{‡}_{ijk}^{(2)}(-2\ddot{I}‰;\ddot{I}‰,\ddot{I}‰)$ finds application in metrology, spectroscopy, telecommunications, material characterization,…