Carcinogenic activity of polycyclic aromatic hydrocarbons in first-principles

Abstract

The first-principles calculations are performed to identify the carcinogenic activities of polycyclic aromatic hydrocarbons. These calculations are performed with the SIESTA code in LDA approximation using unit cell sufficiently big to restrict the interaction between molecules. The carcinogenicity of the PAHs can be identified with the value of HOMO and HOMO-1, the orbital below HOMO, energy gap along with the difference in their contribution to LDOS, calculated over the ring of carbon atoms that contains the highest bond order region. It has been observed that the detaching of the hydrogen atoms from the carbon site changes the LDOS distribution over the carbon atoms.