Conclusions
We have used the HF and DFT methods to
calculate the energy gaps, the density of states and
the total dipole moments of α-quartz SiO2 and doped
α-quartz Si1-xMx O2. The energy gaps of doped
α-quartz Si1-xMx O2 calculated by both HF and DFT
methods are found to reduce as compared to the pure
SiO2 and the narrowest is found in Si17CrO26H32.