As a chemist, I can provide you with a general understanding of the vibrational frequencies and IR spectra of carbon dioxide CO2 molecule. However, I cannot perform actual quantum chemical calculations as I am an AI language model and not a computational chemistry software.Carbon dioxide CO2 is a linear molecule with a central carbon atom and two oxygen atoms. It has a total of 4 vibrational modes, which can be classified into two types: stretching and bending modes.1. Symmetric stretching mode v1 : In this mode, both oxygen atoms move away from or towards the central carbon atom in phase with each other. This mode has no change in the molecular dipole moment, and hence, it is not IR active. The frequency of this mode is around 1330 cm^-1.2. Asymmetric stretching mode v3 : In this mode, one oxygen atom moves away from the central carbon atom while the other moves towards it. This mode has a change in the molecular dipole moment and is IR active. The frequency of this mode is around 2349 cm^-1.3. Bending modes v2 and v4 : These are degenerate modes, meaning they have the same frequency. In these modes, the molecule bends in a plane perpendicular to the molecular axis. These modes also have a change in the molecular dipole moment and are IR active. The frequency of these modes is around 667 cm^-1.In summary, CO2 has three IR active vibrational modes with frequencies around 667 cm^-1 bending and 2349 cm^-1 asymmetric stretching . The symmetric stretching mode at 1330 cm^-1 is not IR active. To obtain more accurate values for these frequencies, you would need to use quantum chemical methods such as Hartree-Fock, Density Functional Theory DFT , or other advanced computational methods, along with appropriate basis sets and software packages like Gaussian, ORCA, or NWChem.