This paper calculated the densities of valence and conduction states for simplified crystalline models of amorphous As2S3and As2Se3. The results are in fairly good agreement with experimental data. The changes of the density of valence states (DOVS) and the optical gap upon varying the bond angle, the bond length and the interlayer distance are also calculated for As2S3. The change of the DOVs by the decrease of the bond angle is found to be similar to the pressure‐induced change of the DOVS observed by Minomura et al.