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Using density functional theory, the elastic and energetic properties of zinc sulphide (ZnS) in the zinc blende and wurtzite solid phases have been calculated with several energy functionals within local density and generalised gradient approximations. We report on the plane-wave energy cut-offs (which determine the size of the basis sets) and k-point mesh density required to achieve energy convergence, and discuss the advantages of each functional with respect to computational expense and accuracy. This study provides a means of optimizing the trade-off between accuracy and computational expense due to the choice of energy functional used in further ab initio studies of ZnS systems, and may serve as a guide as to how one may undertake such testing in the case of other materials. [ABSTRACT FROM AUTHOR]

Zinc sulfide (ZnS) nanoparticles are of interest for their luminescent and catalytic properties which are useful in bio-medical, electronic and photovoltaic devices. However, ZnS nanoparticles undergo reversible and irreversible phase transformations under ambient conditions, which affect the material properties and their biological and environmental significance. In this paper the current knowledge, drawn from experimental, computational and theoretical studies, is reviewed and gaps in this knowledge-base are identified. Based on this assessment, it is suggested that the development of a nanoscale phase diagram for ZnS may provide a way of rapidly assessing the complicated parameter-space occupied by this problem, and serve to highlight the size, temperature, pressure and chemical regimes that may provide the most stable and appropriate size, shape and phase for specific applications. [ABSTRACT FROM AUTHOR]