The molecular structure of 7-methoxy-5-methyl-2-(pyridin-3-yl)-11,12-dihydro-5,11-methano[1,2,4]triazolo[1,5-c][1,3,5]benzoxadiazocine that formulated as (C18H17N5O2) was determined by single-crystal X- ray diffraction and FT-IR spectroscopy. The crystal structure is triclinic, space group P-1 with parameters a = 10.0175(7) angstrom, b = 9.9702(6) angstrom, c = 17.5941(10) angstrom, alpha = 96.546(5)degrees, beta = 106.069(5)degrees gamma=97.178(5)degrees, V = 1654.87(19) angstrom(3), Z = 4. Theoretical calculations have been carried out by using Hartree-Fock (HF) and Density Functional Theory (DFT) methods. The vibrational frequencies were calculated by using HF/6-31G(d,p) and DFT/B3LYP/6-31G(d,p) basis sets in ground state. The calculated structural parameters (bond lengths, bond angles, torsion angles) and vibrational assignments were compared with their experimental data. Molecular Electrostatic Potential (MEP) map of the compound was obtained by using the optimized structures. Furthermore, the frontier molecular orbitals have been created for the compound. Crystal Explorer program was used to determine remarkable interactions in the crystal. (C) 2018 Elsevier B.V. All rights reserved.