A symmetry analysis combined with first-principles calculations of two-dimensional pentagonal materials (PdSeTe, PdSeS, InP5 and GeBi2) based on the Cairo tiling reveal nontrivial spin textures, nodal lines and Weyl points.
Due to the different contribution of the second-order nonlinear coefficient, the pattern of azimuthal angle-dependent SHG from stained Sc2CT2 monolayers depends highly on the strained states.