The relationship between structure and excited-state properties in polyanilines from geminal-based methods.

We employ state-of-the-art quantum chemistry methods to study the structure-to-property relationship in polyanilines (PANIs) of different lengths and oxidation states. Specifically, we focus on leucoemeraldine, emeraldine, and pernigraniline in their tetramer and octamer forms. We scrutinize their structural properties, HOMO and LUMO energies, HOMO-LUMO gaps, and vibrational and electronic spectroscopy using various Density Functional Approximations (DFAs).

Identification of amphetamine as a stimulant drug by pristine and doped C fullerenes: a DFT/TDDFT investigation.

The density functional theory (DFT) was used to examine the electronic reactivity and sensitivity of a pristine, Si, and Al-doped fullerene C with AM drug. AM drug has been shown to be physically absorbed by its N-head on the pristine C with an adsorption energy of about - 1.09 kcal/mol and to have no impact on the electric conductivity of that cluster.