Comment on "planar tetra-coordinate carbon resulting in enhanced third-order nonlinear optical response of metal-terminated graphene nanoribbons" by G.-L. Chai, C.-S. Lin and W.-D. Cheng, J. Mater. Chem., 2012, 22, 11303
Résumé
A discussion about the negative sign of the sizable static second hyperpolarizability of a short zigzag graphene ribbon (C60H 20) reported in G.-L. Chai, C.-S. Lina and W.-D. Cheng, J. Mater. Chem., 2012, 22, 11303 is presented. As shown, the closed-shell singlet configuration of the specific ribbon as described by approximate methods as the HF and DFT causes serious side effects on the computations of electric response properties such as the dipole polarizabilities and the second hyperpolarizability. © 2013 The Royal Society of Chemistry.