“Nanocomposites and nanomaterials”

First principle study of structure and electronic properties of (ZnO)n (n= 96, 120) nanoclusters

R.V. Bovhyra1, D.I. Popovych1, O.V. Bovgyra2
1 Pidstryhach Institute for Applied Problems of Mechanics and Mathematics NAS Ukraine, Naukova 3-B, Lviv, Ukraine
E-mail: bovhyra@gmail.com
2 Ivan Franko National University of Lviv, Faculty of Physics, Kyrylo and Mefodiy 8, 79005-Lviv, Ukraine

We present the results of ab initio density functional theory studies of energy spectrum and ground state parameters of zinc oxide  nanoclusters (ZnO)n (n = 96, 120). Calculations were performed using ultrasoft pseudopotentials in the basis of plane waves. To describe the exchange-correlation energy of the electrons a generalized gradient approximation with Hubbard corrections (GGA+U) was used in Perdew, Burke and Ernzerhof parameterization. Optimization of the nanocluster structure was performed using conjugate gradient method. No symmetry restrictions were used during structure optimization.
In order to determine the most stable structure for the (ZnO)n (n=96, 120) nanoclusters we performed geometry optimization and energy calculations for a number of isomers, including fullerene-like hollow structures that satisfy the rule of six isolated quadrangles, frame layered structures and sodalite-like cage structures built from structural units of (ZnO)12 nanoclusters. The obtained results were then compared with the values obtained in our previous studies for (ZnO)n (n=34, 60) nanoclusters [1].
To analyse the stability of ZnO nanoclusters we calculated binding energy per one molecule of ZnO. Analysis of the obtained energy values shows that in case of (ZnO)96 nanoclusters the most favourable were the fullerene-like hollow structures. All such structures, that satisfy the rule of isolated quadrangles, have been found to have approximately the same binding energy. In the case of (ZnO)120 nanoclusters the most stable configuration was the sodalite-like cage type structure which consists of 16 (ZnO)12 nanoclusters that have joint quadrangle edges.

1.	Bovgyra O.V., Bovhyra R.V., Popovych D.I., Serednytski A.S. Ab inito study of structural and electronic properties of (ZnO)n “magical” nanoclusters n=(34, 60 // Nanoscale Research Letters.-2017.-12:76.