Energetics and elastic properties of large nano-objects: orbital-free approach on the basis of the density functional theory

Cohesive energy E$_{coh}$ and bulk modulus B of large nanosystems C$_n$, Si$_n$, Al$_n$ and Ti$_n$, were calculated in the workframe of the all-electron version of the orbital-free approach on the basis of the density functional theory: number of atoms n was varied up to 4096 for carbon and silicon, 23 328 for aluminum, and 2662 for titanium. Nanosystems were taken as fragments of corresponding crystals. It was found that E$_{coh}$ and B tend to their values known for bulk materials. Therefore, it was convincingly shown that our orbital-free approach could be used successfully for study mechanical properties of large nanosystems.