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.