V2I10P32

Density Functional Theory Calculations- Molecular Structure and Non-Linear Optical Properties of Acetonitrile Molecule

Vinayak Deshmukh^1*

Abstract

Density Functional Theory (DFT) calculations have been employed to investigate the molecular structure and nonlinear optical (NLO) properties of the acetonitrile molecule. The study utilizes the B3LYP functional and 6-311++G(d,p) basis set to optimize molecular geometry and compute relevant electronic properties. Results reveal that acetonitrile possesses a substantial dipole moment and demonstrates notable electronic polarizability (α), first hyperpolarizability (β), and second hyperpolarizability (γ), supporting its suitability for NLO applications. The computed first hyperpolarizability value of acetonitrile is considerably higher than that of standard reference compounds such as urea, indicating enhanced charge-transfer characteristics and molecular planarity that foster increased NLO response. The theoretical absorption spectra align well with experimental values, confirming the reliability of the computational method. These findings advance the understanding of acetonitrile as a promising material in optoelectronic device development, demonstrating that DFT is a reliable approach for predicting and analyzing the NLO behavior of small organic molecules in both gas and solvent phases. The study underscores the importance of molecular structure and electronic configuration in tailoring materials with desirable NLO properties.

Keywords:

Acetonitrile, Density Functional Theory (DFT), Nonlinear Optical Properties (NLO), Hyperpolarizability, Molecular Structure