The metal complexes are getting immense importance as hi-tech functional materials. In the present investigation, a new Zn(II) complex [Zn(C27H35N3)Cl-2] (1) has been synthesized by using 4,4 ',4 ''-tri-tert-butyl-2,2 ':6 ',2 ''-terpyridine ligand. The synthesized compound 1 is characterized by X-ray crystallography, IR spectroscopy as well as elemental analysis. The X-rays structure revealed that compound 1 crystallizes in trigonal space group P3(2)21 in which Zn(II) atom is penta coordinated having highly distorted trigonal bipyramidal geometry. The compound 1 has a 2-fold rotational axis parallel to the b axis, which is passing through two opposite N and C atoms in the central pyridine ring, and the Zn atom. Moreover, quantum computational study has been performed to get insights into the optical and nonlinear optical response properties of compound 1. The geometrical structure of compound 1 has been optimized with M06-2X functional and LANL2DZ/6-311G** basis set and it shows good resemblance with the experimental coordinates. The linear polarizabilities including isotropic (alpha(iso)) and anisotropic (alpha(aniso)) polarizability amplitudes are found to be 69.44 x 10(-24) and 34.99 x 10(-24) esu, respectively. Similarly, the NLO polarizability (& x276c;gamma & x276d;) amplitude for compound 1 is found to be 104.19 x 10(-36) esu at M06-2X method, which is 5 times greater than the p-NA (a model NLO molecule). Additionally, frontier molecular orbitals, molecular electrostatic potentials and Hirshfeld analysis are used to explore the structure-property relationship of compound 1. Thus, the indigenously synthesized compound 1 might be a reasonable candidate for its possible applications as optical and NLO material.