RT Journal Article T1 Two-dimensional Weyl points and nodal lines in pentagonal materials and their optical response A1 Bravo, Sergio A1 Pacheco, Mónica A1 Núñez, Víctor A1 Correa, Julián D. A1 Chico Gómez, Leonor María AB Two-dimensional pentagonal structures based on the Cairo tiling are the basis of a family of layered materials with appealing physical properties. In this work we present a theoretical study of the symmetry-based electronic and optical properties of these pentagonal materials. We provide a complete classification of the space groups that support pentagonal structures for binary and ternary systems. By means of first-principles calculations, the electronic band structures and the local spin textures in momentum space are analyzed for four examples of these materials, namely, PdSeTe, PdSeS, InP5 and GeBi2, all of which are dynamically stable. Our results show that pentagonal structures can be realized in chiral and achiral lattices with Weyl nodes pinned at high-symmetry points and nodal lines along the Brillouin zone boundary; these degeneracies are protected by the combined action of crystalline and time-reversal symmetries. Additionally, we computed the linear and nonlinear optical features of the proposed pentagonal materials and discuss some particular features such as the shift current, which shows an enhancement due to the presence of nodal lines and points, and their possible applications. PB Royal Society of Quemistry SN 2040-3364 YR 2021 FD 2021 LK https://hdl.handle.net/20.500.14352/130837 UL https://hdl.handle.net/20.500.14352/130837 LA eng NO S. Bravo, M. Pacheco, V. Nuñez, J. D. Correa and L. Chico, Nanoscale, 2021, 13, 6117–6128. NO 1201876USM-DGIIP PI-LI 1925211708721120 NO Fondo Nacional de Desarrollo Científico y Tecnológico (Chile) NO European Commission NO Ministerio de Ciencia, Innovación y Universidades (España) NO Agencia Estatal de Investigación (España) NO Universidad Técnica Federico Santa María (Chile) NO Universidad de Medellín DS Docta Complutense RD 8 abr 2026