The electron structure of the Na_1/2Bi_1/2TiO₃ system with ABO₃ type perovskite structure is studied by using self-consult charge-discrete variation-X_α (SCC-DV-X_α) method, and the effect of A, B position substitute on poling characteristic is also analyzed. The calculational results show that spontaneous polarization exists in the NBT piezoceramics system, the piezoelectric properties are enhanced because of the displacement of the B position ions, in addition, the compound substituent of Ba, Sr and Mn ion can decrease coercive field, and increase the strength of spontaneous polarization, so the dielectric properties get improved.

Doping of moderate elements Sb,Te,Ag,Cu can greatly improve the thermoelectric properties of Mg₂Si. For explaning the experimental result,a calculable model is presented.It applies DV-Xα quantum chemistry computation to reveal the micro-structure information, such as the covalent bond grade and the density of state. The calculated results imply that the covalent bond grade of Mg-Si are decreased and the forbidden gaps become narrower after doping. This results appears to be consistent with the experiments.

The electronic structures of Ca₃Co₂O₆ and Ni-doped ones are calculated using density functional and discrete variation method (DFT-DVM).The relation between electronic structure,chemical bond and thermoelectric property is discussed.The results indicate that the highest valence band (HVB) and the lowest conduction band (LCB)are mainly contributed from Co3d,Ni3d and O2p atomic orbitals.The property of semiconductor is shown from the gap between HVB and LCB.The gap of Ni-doped ones is less than that of Ca₃Co₂O₆.The covalent and ionic bonds of Ni-doped ones are both weaker than those of Ca₃Co₂O₆.The thermoelectric property may be improved from adding Ni element into the system of Ca₃Co₂O₆.

The correlation among composition, structure, chemical bond and thermoelectric property of skutterudites of IrSb₃, Ir₄NdGe₃Sb₉ and Ir₄SmGe₃Sb₉ is studied using SCF-DV-X_α method, one of calculation methods in quantum chemistry. Ir₄NdGe₃Sb₉ and Ir₄SmGe₃Sb₉ are calculated with several models for investigating the "rattling" patterns. The results show that the model with rare earth near to Ge is more stable than that with rare earth near to Sb, and the former is with lower thermal conductivity. The covalent bonds of Ir₄SmNdGe₃Sb₉ are weaker than those of Ir₄SmGe₃Sb₉, and those of Ir₄NdGe₃Sb₉ and Ir₄SmGe₃Sb₉ are both weaker than those of IrSb₃, which is consistent with the experimental result of thermal conductivity.