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Optimum resolution data of X-ray pow- der diffraction for 7-amino desacetoxy cephalospo- ranic acid(7-ADCA) were collected from an X′ Pert Pro MPD diffractometer with the setup of 0.01°/s and 0.01° per step. Indexing to the crystal system and searching space group from the diffraction data were conducted by means of the computational crystal- lography method. The pilot crystal models of 7-ADCA were then refined by Rietveld method to obtain the exact three-dimensional structure. The results show that the crystal structure of 7-ADCA is monoclinic, space group P21 with unit cell dimensions a=13.50 ?, b=6.01 ?, c =5.91 ?, α= γ =90.00°, β =101.96°, Z=2 and V =469.10 ?3. The fraction coordinate of each atom in the unit cell is well located and reported.
Optimum resolution data of X-ray powder-diffraction for 7-amino desacetoxy cephalospo-ranic acid (7-ADCA) were collected from an X ’Pert Pro MPD diffractometer with the setup of 0.01 ° / s and 0.01 ° per step. Indexing to the crystal system and searching space group from the diffraction data were conducted by means of the computational crystal-lography method. The pilot crystal models of 7-ADCA were then refined by Rietveld method to obtain the exact three-dimensional structure. The results show that the crystal structure of 7-ADCA is monoclinic, space group P21 with unit cell dimensions a = 13.50 ?, b = 6.01 ?, c = 5.91 ?,? =? = 90.00 °,? = 101.96 °, Z = 2 and V = 469.10 -3. The fraction coordinate of each atom in the unit cell is well located and reported.