The authors report parameter-free, self-consistent, electronic-structure and total-energy calculations for chalcogen point defects in crystalline silicon. Both possible defect sites of tetrahedral symmetry are investigated. The calculated total energies are discussed in terms of dissolution and reaction energies. From these, the stable defect position is identified as substitutional. The comparison of the theoretical results (spin and ground-state wave function) with experimental data such as infrared-absorption, EPR, and ENDOR spectra further supports this identification.
 

Physical Review Letters, 54 2525-8, 1985.