First-Principles Study Of Solid-State Properties Of Adrenergic Neurotransmitters, Orthorhombic Noradrenaline, And Monoclinic Adrenaline

Using the density functional theory with the approximation of the generalized gradient approximation, we carried out a theoretical investigation of the structural, optoelectronic, vibrational (IR and Raman), and thermodynamic properties of the noradrenaline (NA) and adrenaline (AD) crystals. The lattice parameters showed good agreement with the experimental data, and an indirect bandgap was obtained for both structures. The calculated optical properties showed that the crystal of noradrenaline has a slightly higher sensitivity than adrenaline, and the absorption of both crystalline structures occurs in the UV region, showing greater sensitivity to electromagnetic radiation with an energy of approximately 5 eV and a dielectric constant of approximately 2.50 for NA and AD. Finally, IR and Raman spectra were presented, and a thermodynamic analysis showed that the adrenaline crystal is more stable than the noradrenaline crystal as the temperature increases.