First-principles study of structures and electronic properties of cadmium sulfide clusters

The lowest-energy structures and the electronic properties of CdGGA, DMol$^{3}$, energy gap, binding energyProject supported by the National Natural Science Foundation of China (Grant Nos 90306010 and 20371015) and the Program for New Century Excellent Talents in University, Chinese Ministry of Education (Grant No NCET-04-0653).3640, 3640B, 7115MThe lowest-energy structures and the electronic properties of CdGGA, DMol$^{3}$, energy gap, binding energyProject supported by the National Natural Science Foundation of China (Grant Nos 90306010 and 20371015) and the Program for New Century Excellent Talents in University, Chinese Ministry of Education (Grant No NCET-04-0653).3640, 3640B, 7115MThe lowest-energy structures and the electronic properties of Cd$_{n}$S$_{n}$ ($n=1-8$) clusters have been studied by using density-functional theory simulating package DMol$^{3}$ in the generalized gradient approximation (GGA). The ring-like structures are the lowest-energy configurations for $n=2, 3$ and the three-dimensional spheroid configurations for $n=4-8$. The three-dimensional structures may be considered as being built from the Cd$_{2}$S$_{2}$ and Cd$_{3}$S$_{3}$ rings. Compared to the previous reports, we have found the more stable structures for Cd$_{n}$S$_{n}$($n=7,8$). Calculations show that the magic numbers of Cd$_{n}$S$_{n}$ ($n=1-8$) clusters are $n=3$ and 6. As cluster size increases, the properties of Cd$_{n}$S$_{n}$ clusters tend to bulk-like ones in binding energy per CdS unit and Mulliken atomic charge, obtained by comparing with the calculated results of the wurtzite and zinc blende CdS for the same simulating parameters.