I simulated a BN nanotube in ATK. Tried to find the optimum bond length by comparing a few total energies in different simulations. However confused a bit. It might be a simple question but is the bond length with the total energy -12542.8760 eV or -12542.6181 eV better? Which is closer to the lowest energy point? Do I have to compare the absolute values or with the (-) sign? Thanks...
