Alireza Heidari^{1, 2,}, Jennifer Esposito¹, Angela Caissutti¹

Parameters such as FT–IR and Raman vibrational wavelengths and intensities for single crystal Botulinum Toxin are calculated using density functional theory and were compared with empirical results. The investigation about vibrational spectrum of cycle dimers in crystal with carboxyl groups from each molecule of acid was shown that it leads to create Hydrogen bonds for adjacent molecules. The current study aimed to investigate the possibility of simulating the empirical values. Analysis of vibrational spectrum of Botulinum Toxin is performed based on theoretical simulation and FT–IR empirical spectrum and Raman empirical spectrum using density functional theory in levels of HF/6–31G*, HF/6–31++G**, MP2/6–31G, MP2/6–31++G**, BLYP/6–31G, BLYP/6–31++G**, B3LYP/6–31G and B3LYP6–31–HEG**. Vibration modes of methylene, carboxyl acid and phenyl cycle are separately investigated. The obtained values confirm high accuracy and validity of results obtained from calculations.

Vibronic Structure, Vibrational Spectra Analysis, Density Functional Theory (DFT), Botulinum Toxin, Non–Focal Functions of Becke, Correlation Functions of Lee–Yang–Parr, Time–Resolved Absorption and Resonance, FT–IR and Raman Biospectroscopy