Abstract
The g-values of the ESR signal have been calculated for dangling bonds in amorphous C, Si and Ge and for weak bonds in amorphous Si by using the EHT method. Effects on g-values of changing the bond angle, bond length and dihedral angle have been calculated and found that the change of g-values due to fluctuations of the amorphous structure is dominated by the change of the bond angle. Although the calculated g-values depend on the cluster size, the results are useful for qualitative considerations on the dangling bonds and the weak bonds.