Structure, stability, and infrared spectrum of capped carbon cones: A DFTB study

Capped carbon cones, known as carbon nanohorns (CNHs), are currently considered to be promising drug carrier agents. To explore the drug-carrying ability and other properties for practical use, the chemistry of production, functionalization, and characteristics of CNHs must be elucidated. To this end, molecular modeling can complement the experimental results by providing the molecular properties for single idealized molecules. In the present study, distinct structures for CNHs are proposed, and their equilibrium geometries, stability, and infrared spectrum are discussed. In addition to the opening angle of the cone, the topology of the tips was also changed, giving rise to 12 distinct geometries, which were analyzed by using the density functional-based tight binding approach (DFTB).