Presented here is our continuing first-principles density functional theory study of the structural stability of a select group of dopants in diamond nanocrystals. On the basis of the work of others concerning dopants in diamond and endohedral atoms in fullerenes, the dopants selected for use here are oxygen, aluminum, silicon, phosphorus, and sulfur. These atoms were included substitutionally in the center of a 29-carbon-atom nanodiamond crystal, and each structure was relaxed using the Vienna Ab Initio Simulation Package. We describe the bonding and structure of the relaxed doped nanocrystals via examination of the electron charge density and point group symmetry. In combination with our previously reported results, it is anticipated that these results will assist in providing a better understanding of the mechanical stability of doped nanodiamonds for use in diamond nanodevices.