Molecular docking, spectroscopic studies and quantum calculations on nootropic drug J. Uma Maheswari a,b,⇑ , S. Muthu c , Tom Sundius d a Research Scholar, Sri Chandrasekharendra Saraswathi Viswa Mahavidyalaya, Kanchipuram 631561, Tamil Nadu, India b Department of Physics, DMI College of Engineering, Palanchur, Tamil Nadu, India c Department of Physics, Sri Venkateswara College of Engineering, Pennalur, Tamil Nadu, India d Department of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki, Finland highlights  Piracetam is one of the groups of racetams.  Description of the molecular geometry and molecular vibrational of the piracetam.  Docking using Q-site finder and target protein is geometrically optimized.  The values of b and l suggest the possibility of technological (NLO) applications. graphical abstract Piracetam improves the function of the neurotransmitter acetylcholine muscarinic cholinergic receptors, which are implicated in memory process. Among the possible therapeutic interventions, 2-pyrrolidine derivatives such as piracetam and related nootropics are currently used for their facilitatory effects in learning and memory in animal models. article info Article history: Received 27 September 2013 Received in revised form 16 November 2013 Accepted 5 December 2013 Available online 11 December 2013 Keywords: FT-Raman Vibrational analysis NCA PES TD-DFT Docking abstract A systematic vibrational spectroscopic assignment and analysis of piracetam [(2-oxo-1-pyrrolidineaceta- mide)] have been carried out using FT-IR and FT-Raman spectral data. The vibrational analysis was aided by an electronic structure calculation based on the hybrid density functional method B3LYP using a 6- 311G++(d,p) basis set. Molecular equilibrium geometries, electronic energies, IR and Raman intensities, and harmonic vibrational frequencies have been computed. The assignments are based on the experimen- tal IR and Raman spectra, and a complete assignment of the observed spectra has been proposed. The UV– visible spectrum of the compound was recorded and the electronic properties, such as HOMO and LUMO energies and the maximum absorption wavelengths k max were determined by the time-dependent DFT (TD-DFT) method. The geometrical parameters, vibrational frequencies and absorption wavelengths were compared with the experimental data. The complete vibrational assignments are performed on the basis of the potential energy distributions (PED) of the vibrational modes in terms of natural internal coordi- nates. The simulated FT-IR, FT-Raman, and UV spectra of the title compound have been constructed. Molecular docking studies have been carried out in the active site of piracetam by using Argus Lab. In addi- tion, the potential energy surface, HOMO and LUMO energies, first-order hyperpolarizability and the molecular electrostatic potential have been computed. Ó 2014 Elsevier B.V. All rights reserved. 1386-1425/$ - see front matter Ó 2014 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2013.12.011 ⇑ Corresponding author. Tel.: +91 7845681258. E-mail address: umas.umas@gmail.com (J. Uma Maheswari). Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 123 (2014) 503–510 Contents lists available at ScienceDirect Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa