In the context of a full-potential orbital-free approach for the modeling of multi-atomic systems we investigated the dependence of the cohesive energies and bulk elastic modules of the large nanosystems Cn (n is up to 4096 atoms), Aln (n is up to 23,328 atoms) and tin (n is up to 2160 atoms). It was shown that the cohesive energies and elastic modules tend towards bulk crystal values at n ≈ 3000 for Cn systems, at n ≈ 1500 for Tin and at n ≈ 20,000 for Aln. The execution time for one energy iteration for Ti23328 was only 23 min.