Ab initio study of charged states of H in amorphous SiO2

We carried out an ab initio investigation of the charged states of hydrogen in amorphous SiO2 using a previously generated model structure. We found a large variety of equilibrium configurations as a result of the disordered atomic structure in our model system. The formation energies of H-0, H+ and H- remain nevertheless close to the energetics found for a-quartz, with the charged species always more stable than the neutral one irrespective of the electron Fermi level.