Theoretical investigation on the second hyperpolarizabilities of open-shell singlet systems by spin-unrestricted density functional theory with long-range correction: Range separating parameter dependence

The spin-unrestricted density functional theory with long-range correction, LC-UBLYP, method with range separating parameter μ = 0.3-0.5 is adequate for calculating the second hyperpolarizabilities (γ) for conjugated diradical systems.