Single-crystal x-ray diffraction at high pressures

Construc tion and ope ration or a high·pressure single·c rys lal x·ray d iffract ion precess ion camera is described . The inslrument appears app li cable to single crystal s tudi es 10 pressures as high as al least 30 kilobars a nd te mperatures or a t leas l 250 °C. Application or Ih e instrume nl is illustrated by single crystal s tudi es or ice VI and ice VII. Unit cell parame ters are given ror these Iwo rorms or ice. Further modifications a nd app lications are di scussed.