  The atomic structure and physical properties of few-layered <111> oriented
diamond nanocrystals (diamanes), covered by hydrogen atoms from both sides are
studied using electronic band structure calculations. It was shown that energy
stability linear increases upon increasing of the thickness of proposed
structures. All 2D carbon films display direct dielectric band gaps with
nonlinear quantum confinement response upon the thickness. Elastic properties
of diamanes reveal complex dependence upon increasing of the number of <111>
layers. All theoretical results were compared with available experimental data.
