Nanoelectronics and photonics applications of single wall carbon nanotubes (SWNT) are feasible only if SWNTs have specific chirality. The knowledge of the detailed mechanism for SWNT synthesis would allow one to optimize the chemical vapor deposition (CVD) process and may help to gain control over selectivity of SWNT synthesis. While it is not probably feasible to study this mechanism experimentally, it could be analyzed using molecular simulations. Here we propose multiscale computer modeling of CVD process. High theory level can be used for di- and tri-atomic fragments, in order to generate parameters for bond order force field. In turn, force field simulations will be used to characterize the chemical origin and thermochemical properties of the intermediates and transition states. This will allow predicting the rate constants for the elementary steps, which are then used in kinetic Monte Carlo simulations to describe SWNT growth at realistic time scales.