Multiply twinned particles, such as decahedra and icosahedra, in diamond cubic crystals were explained by using kinetic Monte Carlo simulations of the sequential occurrence of 2 and 3 stacking faults on different {111} surfaces during vapor-phase growth. The same simulations, using single adatom adsorption and the desorption of singly-bonded sites, failed to predict the kinetic faceting of the commonly observed so-called star-shaped decahedron. A set of kinetic Monte Carlo simulations were performed here by using an additional reaction step for the etching of doubly-bonded surface sites during growth; starting with a seed crystal that contained 2 stacking errors. These simulations produced star-shaped decahedral crystals and thus suggested a possible explanation for the observed star-shaped decahedral morphology in diamond crystals. Experimental results on the morphological evolution of star-decahedral crystals revealed a sequence in which an intermediate shape, between decahedron and icosahedron, developed into a more complete icosahedral shape upon further growth.

Kinetic Faceting of Multiply Twinned Diamond Crystals during Vapor Phase Synthesis. R.C.Mani, M.K.Sunkara: Diamond and Related Materials, 2003, 12[3-7], 324-9