Thermal stability of hexaprismane C$_{12}$H$_{12}$ and octaprismane C$_{16}$H$_{16}$

The results of quantum-mechanical calculations of elementary prismanes–hexaprismane C$_{12}$H$_{12}$ and octaprismane C$_{16}$H$_{16}$ – have been presented. Their stability has been investigated in terms of the density functional theory and nonorthogonal tight-binding model, and the heights of potential barriers preventing isomerization and decay have been determined. It has been established based on the analysis of the molecular dynamics data and the hypersurface of the potential energy of these metastable compounds that hexaprismane and octaprismane have a rather high kinetic stability, which indicates the possibility of the formation of carbon polyprismanes for applications in microelectronics and nanoelectronics, power engineering, pharmaceutics, metrology, and information technologies.