A molecular-orbital study of the bond-length variations in lithium polysilicate

Bond-length variations within the SiO₄ and LiO₄ tetrahedra in (Li₂SiO₃)_x are examined in terms of valence-electron population analyses obtained from extended Hückel molecular orbital theory. The results indicate that a significant improvement in the correlations between observed bond length and Mulliken overlap population is obtained when the 'first coordination sphere' of tetrahedral groups is included in the calculations.