Hollow structures of Ti_nO_m systems with m ≈ 2n: A density functional theoretical study

We performed density-functional-theoretical calculations of almost stoichiometric structures of hollow cages of Ti_nO_m systems with m ≈ 2n. We study the stability of Ti_nO_m hollow particles of different sizes and shapes for systems between 80 and 110 atoms using the binding energy as stability criterion. These cages could be useful in electrochemiluminescenece sensors, energy systems, encapsulation of beauty ingredients, and even in biomedical applications. Our results suggest the possible existence of such structures in a great variety of geometrical shapes with small binding energy differences among them, thus presenting a very dense spectrum of possible metastable configurations. Different initial seeds converge to the same final structures, which is also a signature for stability. These results are along the line of experiments in larger size systems, which demonstrate the feasibility of these structures without apparent size limitations.