DFT Calculation is a very useful skill to determinate deferent parameters into a molecule:
Bond lengths are accurate to within 1-2%
Within 5-10% accuracy
Desired accuracy for hybrid functionals
Ionization and affinity energies
Average error around 0.2 eV for hybrid functionals
But, we have to take into account the limitations of DFT :
The Band gap is a problem, and an overbidding (LSDA calculations usually give too large cohesive energies or too high bulk moduli.