Investigation on the electronic structures and nonlinear optical properties of alkali metal atom doped all‐cis 1,2,3,4,5,6‐hexafluorocyclohexane

On the basis of stable all‐cis 1,2,3,4,5,6‐hexafluorocyclohexane, a series of alkali metal atom doped M F₆C₆H₆ (M = Li, Na, and K) compounds were theoretically constructed and studied by using ab initio quantum chemistry method. The calculated results show that the HOMO–LUMO gap of the M F₆C₆H₆ conspicuously narrowed from 10.41 eV of pure F₆C₆H₆ to about 2.00 eV of M F₆C₆H₆. The electride characteristics of M F₆C₆H₆ are verified by their electronic structures, HOMOs, and small VIE values. As expected, these electrides possess considerable static first hyperpolarizabilities (β₀). Among the studied electrides, the largest β₀ of the Li F₆C₆H₆ is 7.00 × 10⁵ au, which is about 3030 times larger than pure F₆C₆H₆. TD‐M06‐2X calculations show that these larger β₀ values are attributed to lower transition energies for the crucial excited states of M F₆C₆H₆ systems. Further, the vibrational contributions to the static first hyperpolarizabilities of these molecules are also estimated. Moreover, Li atom doped dimer and trimer of F₆C₆H₆ also present unusual electride's features and exhibit dramatically large β₀. Thus, the F₆C₆H₆ interacting with the alkali metal atoms may be a potential promising NLO nanomaterial.