Ab Initio Structure Analysis Using Laboratory Powder Diffraction Data
نویسندگان
چکیده
منابع مشابه
Structure of Zeolitic K2TiSi3O9•H2O Determined ab initio from Powder Diffraction Data
— The crystal structure of K2TiSi3O9•H2O has been solved ab initio from X-ray powder data. The unit cell is orthorhombic (space group P212121, Z = 4) with cell dimensions a = 7.1362(2) Å, b = 9.9084(3) Å, c = 12.9414(4) Å, V = 915.07 Å. The structural model was obtained from direct methods using 455 integrated intensities. The Rietveld refinement converged to final Bragg and profile indicators ...
متن کاملStructure of α-NaCaAlF6 determined ab initio from conventional powder diffraction data
— α-NaCaAlF6 is prepared by solid state reaction as poor quality crystals. The structure is determined ab initio from conventional X-ray powder data. The cell is monoclinic, space group P21/c, Z = 8, with a = 8.7423(3) Å, b = 5.1927(2) Å, c = 20.3514(9) Å and β = 91.499(2)°. The final Rietveld refinement leads to RP = 10.6 % and RB = 5.2 %. The structure is built up from isolated AlF6 octahedra...
متن کاملCombined method for ab initio structure solution from powder diffraction data
A new direct-space method for ab initio solution of crystal structures from powder diffraction diagrams is presented. The approach consists of a combined global optimization (`Pareto optimization') of the difference between the calculated and the measured diffraction pattern and of the potential energy of the system. This concept has been tested successfully on a large variety of ionic and inte...
متن کاملSynthesis and Crystal Structure of α-Ba2ZrF8 and Pb2ZrF8 Determined ab initio from Synchrotron and Neutron Powder Diffraction Data
— α-Ba2ZrF8 is prepared as systematically twinned crystals by hydrothermal synthesis (200°C) or as fine powders either on a sand bath (60°C) (aqueous HF medium) or by solid state reaction at 450°C. Synchrotron radiation was used because of ambiguities in indexations from conventional X-ray (pseudo-hexagonal symmetry). The structure was determined ab initio from synchrotron powder data. Neutron ...
متن کاملStructure determination from powder diffraction data.
Advances made over the past decade in structure determination from powder diffraction data are reviewed with particular emphasis on algorithmic developments and the successes and limitations of the technique. While global optimization methods have been successful in the solution of molecular crystal structures, new methods are required to make the solution of inorganic crystal structures more r...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nihon Kessho Gakkaishi
سال: 2011
ISSN: 0369-4585,1884-5576
DOI: 10.5940/jcrsj.53.312