https://www.psi.ir/physics_society_iran_1_homeIranian Journal of Physics Research1682-695721420220220Potential energy surface, quartic force fields and vibrational levels of chlorine dioxide anionPotential energy surface, quartic force fields and vibrational levels of chlorine dioxide anion775782175710.47176/ijpr.21.4.41238FAAShayestehSchool of Chemistry, College of Science, University of Tehran, Tehran, Iran0000-0002-6151-7885EFalatooniSchool of Chemistry, College of Science, University of Tehran, Tehran, IranMMotallebipourSchool of Chemistry, College of Science, University of Tehran, Tehran, IranJournal Article20210423Potential energy surface was calculated for the ground electronic state of the triatomic ion ClO<sub>2</sub><sup>−</sup> using the coupled-cluster method CCSD(T). Calculations were carried out for 1200 points on the potential energy surface, and the calculated points were fitted to the potential energy expression in terms of the internal coordinates, from which the quadratic, cubic and quartic force fields were determined. Using the second-order rovibrational perturbation theory, harmonic vibrational frequencies, anharmonicity constants and several other spectroscopic parameters were calculated, and accurate fundamental vibrational frequencies were obtained. Also, the energies of 30 lowest vibrational levels were calculated using the anharmonicity constants.<br /> Potential energy surface was calculated for the ground electronic state of the triatomic ion ClO<sub>2</sub><sup>−</sup> using the coupled-cluster method CCSD(T). Calculations were carried out for 1200 points on the potential energy surface, and the calculated points were fitted to the potential energy expression in terms of the internal coordinates, from which the quadratic, cubic and quartic force fields were determined. Using the second-order rovibrational perturbation theory, harmonic vibrational frequencies, anharmonicity constants and several other spectroscopic parameters were calculated, and accurate fundamental vibrational frequencies were obtained. Also, the energies of 30 lowest vibrational levels were calculated using the anharmonicity constants.<br /> https://ijpr.iut.ac.ir/article_1757_e11674109d956934497c1195876b1968.pdf