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The magnetic susceptibilities of liquid Ag–In, Ag–Sn, Ag–Ga and Ag–Zn alloy systems have been measured over a wide temperature range from 600 to 1085° C. The magnetic susceptibility curves at 1010° C were plotted against the alloy composition, which are different from one another. The temperature coefficients of their magnetic susceptibilities against the composition were very similar, showing a sharp minimum at about 90 at%Ag and a broad maximum at about 70 at%Ag, except for those of the Ag–Zn system. The curve of the concentration-concentration fluctuation in the long wavelength limit S CC (0) of those alloys has been estimated by using the experimental EMF data compiled in the literatures. Two pronounced minima exist in the S CC (0) curves at about 35 and 70 at%Ag, except for the Ag–Ga system.

The magnetic susceptibilities of molten cuprous halides and their mixtures have been measured as a function of temperature. The temperature dependence of susceptibilities in molten CuBr and CuI show small paramagnetic deviations compared to those in molten potassium halides. The composition dependence of CuCl–CuI and CuBr–CuI melts obey the Wiedemann rule, while the molten CuCl–CuBr system exhibits a large deviation from this rule.

Variational approach was considered for the energy band theory in the case of non-muffin-tin potentials. A functional was investigated for the variational procedure under the natural boundary condition. Matrix elements were obtained for the determination of energy bands in the general case of non-muffin-tin potentials. A model calculation was performed for the one dimensional empty case. Correct energy values were obtained.

The effective Hamiltonian for an electron trapped in a donor (acceptor) atom is derived from the Hamiltonian of the total system by taking account of the polarization effect of the medium on the basis of many-body treatment. As a result, an expression which enables us to calculate the impurity potential in the immediate vicinity of the impurity center is presented. One can also prove exactly by this expression that the impurity potential at a long distance from the impurity center is screened by the static dielectric constant of the host crystal for a uniform field.

The properties of the dielectric constants, defined by using many-body theory, are considered. Especially, their dependence upon wave vectors is discussed. Internal dielectric constant for impurity potential in an insulator is shown to have no anomalous behavior at reciprocal lattice vectors. It is also shown that contribution to the dielectric constant from Umklapp terms vanishes at k =0.

The wave-number-dependent dielectric function is calculated for crystalline KCl, on the basis of the expressions derived in a previous paper. The value, 2.383, is obtained for the static dielectric constant in long wave length limit, which is to be compared with the observed optical dielectric constant e ∞ =2.13. The contribution from the Umklapp terms has turned out to be rather small. An approximate analytical expression is presented for the screened Coulomb potential in KCl crystal.

A theoretical treatment of the edge structure of the fundamental optical absorption of alkali halide crystals is developed on the basis of Slater-Koster and Clogston's treatment of impurity levels. It is concluded that the absorption shoulder characteristic of alkali halides is attributed to the onset of band-to-band transition or to the transition to the excited exciton states with principal quantum number n =2. Numerical calculation is made for the absorption structure of KCl.

Deformation potential constants of wurtzite type CdS are calculated by the OPW method. The results are as follows: \begin{aligned} {D_{1}}^{1}-{D_{1}}^{6}{=}-6.2\ \text{eV} \text{and} {D_{2}}^{1}-{D_{2}}^{6}{=}-5.2\ \text{eV}. \end{aligned} The experimental values to be compared with these are respectively \begin{aligned} C_{1}+C_{3}/2{=}-3.05{\pm}0.5\ \text{eV} \text{and} C_{2}+C_{4}/2{=}-2.95{\pm}0.5\ \text{eV}. \end{aligned}

Energy bands of the crystalline Argon have been calculated with a potential based upon the Ewalt potential by MS method. Effects of the virial theoretical α were included in the core charge density. For the crystal, α was inccreased gradually up to 1 in the course of the self-consistent energy band calculation. The best band gap is obtained with α=1. Electron affinity was improved by about 2 eV.