5. CONCLUSIONS
In this work, the rotational and vibrational data has been computed for the conformers of Leucine and various isomeric species located along the gas-phase stereoinversion pathways of Leucine. Notably, the isomeric species investigated exhibits diverse chemistry. For these species, the rotational parameters were quantum-mechanically calculated employing MP2 theory whereas the anharmonically corrected vibrational data was computed using DFT while incorporating the dispersion effects. The computed spectral data is found to be in excellent agreement with the available experimental data for the global conformer of Leucine. The rotational line data provided in this work in the frequency range of 10000 MHz to 45000 MHz though belongs only to the low frequency region but can be extended to any usable range utilizing the rotational parameters computed in the present work. A detailed vibrational analysis using PED calculations has also been provided for all the fundamental vibrational modes, in mid-infrared to far infrared regions. The spectroscopic data provided in this work can be quite reliable for assisting any search for amino acid Leucine in outer space.