The crystal structure of KCdF3 is determined in the third, orthorhombic phase and refined by using a full matrix least-squares method by taking domain structures into consideration. Refinement is performed with superlattice-X, M and R point reflection intensity data collected on the multiple-film Weissenberg photographs taken with filtered MoKα radiation. Pbnm-D16 2h (z = 4) is assigned to the space group of KCdF3. The R value reaches 8 % for the intensity data of the X and M point reflections. When the R point reflections are included in the calculation, the R value is 9.8 %. The structure is well described by the successive condensations of M3 and Z5 (Rx25 + Ry 25-like) soft-phonon modes

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Dynamical properties of a triangular loop, each side of which consists of one Josephson junction with zero capacitance and inductance, are considered in this paper. For two kinds of applied currents, phase-time and current-voltage relations are calculated by integrating a set of derived nonlinear differential equations numerically. Time dependence of a fluxoid number in the loop is given by phase-time relations, and it is found that the calculated current-voltage relations exhibit uneven changes slightly above the threshold current for the voltage shifting from two to three junctions. The analytical result for the threshold currents under some conditions is in good agreement with the numerical one.