ABSTRACT — The paper reviews some of the problems encountered in the measurement and interpretation of electron-density measurements. The experimental problems are compared with those encountered in parallel studies of spin density distributions.
ABSTRACT — Ferroelastic transformations can be calculated, when an n-fold pseudo-rotation exists (the n-fold rotation being a symmetry element of the prototype lost in the lower symmetry ferroelastic phase ), by means of a transformation (rotation of axes) corresponding to the reorientation of the lattice vectors if distortion of the ferroelastic structure is taken into account.
RESUME —Apartir de l’étude des modes normaux de vibration des molécules d’eau d’hydratation, par spectroscopie Raman, et de données de diffraction de Rayons-X nous repportons la orientation précise des hydrogénes dans le La2 (SO4)3 .9 H2O.
ABSTRACT — The standard representation recently proposed by the author, and applied in detail to structures based on cubic and hexagonal closest packings, has been extended to inorganic structures based on simple and on loose packings. This standard representation clearly shows that these structures have a much simpler atomic organization and are more interrelated than could be imagined using conventional ways of structure representation.
ABSTRACT — Polyhedra around the atomic sites of the sigma phase structure were defined in a way similar to Wigner-Seitz cell and computer programs for the calculation of their volumes were written; the apllication to the sigma phase Mo3Co2 shows that again the J-sites exhibit a peculiar behaviour.
ABSTRACT — The o-phase structure V62 Co38 has been studied using an X-ray single-crystal diffractometer. Both size and electronic factors appear to account for a complete ordering of this phase which is approximately stoichiometric.
ABSTRACT —Avery sensitive a. c. method is described for the measurement of the Hall effect in metals. It uses a high quality lock’in amplifier with the oscillator incorporated, an operational power supply, and a low noise step-up transformer to rise the signal level.