Nonlinear optical response of Li n ClK (n = 1–6) superalkali clusters

Abstract

Abstract The geometrical structures, stabilities, electronic properties and nonlinear optical response of the halogen doped bimetallic Li n ClK (n = 1–6) clusters were studied within the density functional theory. Based on the dissociation energy, second order energy difference and GH-L (HOMO-LUMO gap), the Li n ClK (n = 2, 4, 6) clusters are more stable. According to their ionization energies, the clusters can be classified as a superalkali. From the NBO analysis, the clusters are excess electron systems. The obtained first static hyperpolarizability (β o) values are in the range of 1.56 × 104 − 4.33 × 104 au while the second static hyperpolarizability vary within 2.47 × 106 au to 13.9 × 106 au for the Li n ClK (n = 1–6) superalkalis that are slightly higher than the nonlinear optical response of halogen doped monometallic clusters. More importantly, the Li5ClK is transparent in the deep UV region (λ < 300 nm) among the superalkalis indicating that the Li5ClK superalkali can be a candidate structure as new member of NLO materials.