On the splitting of the exciton ground state in silicon

The exciton ground state in silicon is calculated taking into accoun the effect of the split-off valence band. We show that this effect is very important. The anisotropy splitting of the ground state is found to be 0.32 meV, while a previous analysis, which neglected the split-off band, gave 0.46 meV. The new result is in good agreement with recent experimental data. © 1979.