Research Article Density Functional Theoretical Computational Studies on 3-Methyl 2-Vinyl Pyridinium Phosphate N. Kanagathara , 1 V. J. Thanigaiarasu, 2 V. Sabari, 3 and S. Elangovan 4 1 Department of Physics, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, andalam, Chennai-602 105, India 2 Department of Physics, Jaya Arts and Science College, iruninravur, Chennai-602024, India 3 Department of Physics, Marudhar Kesari Jain College for Women, Vaniyambadi, Tamilnadu-635 751, India 4 Department of Physics, College of Natural and Computational Sciences, Wollega University, Nekemte-395, Ethiopia Correspondence should be addressed to S. Elangovan; elangovan.physics@rediffmail.com Received 3 May 2022; Revised 14 July 2022; Accepted 28 July 2022; Published 18 August 2022 Academic Editor: Sefer Bora Lisesivdin Copyright © 2022 N. Kanagathara et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. e molecular structure of 3-methyl 2-vinyl pyridinium phosphate (3M2VPP) has been optimized by using Density Functional eory using B3LYP hybrid functional with 6-311++G (d, p) basis set in order to find the whole characteristics of the molecular complex. e theoretical structural parameters such as bond length, bond angle, and dihedral angle are determined by DFT methods and are well agreed with the single crystal X-ray diffraction parameters. eoretical vibrational, highest occupied molecular orbital - lowest unoccupied molecular orbital (HOMO-LUMO), natural bonding orbital (NBO), and electrostatic potential (ESP) analyses have also been performed. Based on the potential energy distribution (PED), the complete vibrational assignments, analysis, and correlation of the compound’s fundamental modes have been determined. Natural bonding orbital (NBO) analysis is used to evaluate the intramolecular charge transfer and hyper-conjugative interaction of the molecule. B3LYP/6- 311++G (d, p) basis set determines the electronic properties such as HOMO–LUMO energies and is used to understand the kinetic stability and chemical reactivity of the studied compound. Molecular electrostatic potential (MEP) is used to investigate the electron density distribution and chemical reactive sites of 3M2VPP. e dipole moment, total polarizability, and the first-order hyperpolarizability calculations have been carried out for the studied molecule. Hirshfeld surface analysis has been done to study the intermolecular interactions in the studied complex. 1. Introduction Organic aromatic materials with the ability of charge transfer have attracted many researchers for the past two decades and have been recognized as a material for the development of nonlinear optical materials [1, 2]. Organic phosphates are highly lustrous, adherent, and ductile, and their additives are used in electroplating baths. Structure, as well as biological activities of thiazolo-pyridine dicarboxylic derivatives, were reported by Yahia et al. [3]. Linear, as well as nonlinear optical properties of pyridine N-oxide, were reported by Soscun et al. [4]. Phosphoric acid pyridine-1- ium-2-carboxylate has been identified as a potential nonlinear optical material and is useful for device fabrication [5]. ere are many reports available for the pyridine de- rivatives applications in the nonlinear optical field [6–10]. Pyridinium salts and its derivatives are found in various natural and bioactive compounds [11]. It has wide appli- cations such as acylating agents and phase transfer catalysts and has found use in industrial applications such as dyes, surfactants, cosmetics, pharmaceuticals, polymerization, phase transfer agents, catalysis, sensors, and electrolytes [12]. In continuation of research on possible and potential ap- plications of pyridine and its salts, the present study is aimed to study the quantum chemical computations of 3-methyl 2- vinyl pyridinium phosphate. e structure of 3-methyl 2- Hindawi Advances in Condensed Matter Physics Volume 2022, Article ID 6488234, 14 pages https://doi.org/10.1155/2022/6488234