Zobrazeno 1 - 10
of 40
pro vyhledávání: '"KARL F. FISCHER"'
Publikováno v:
Crystals, Vol 14, Iss 8, p 684 (2024)
The Parameter Space Concept (PSC) is an alternative approach to solving and refining (partial) crystal structures from very few pre-chosen X-ray or neutron diffraction amplitudes without the use of Fourier inversion. PSC interprets those amplitudes a
Externí odkaz:
https://doaj.org/article/d66da69822544390aa19ba3bde28c462
Autor:
Armin Kirfel, Karl F. Fischer
Publikováno v:
Zeitschrift für Kristallographie - Crystalline Materials. 230:439-448
Two-dimensional equal atom structures or structure projections are determined applying the parameter space concept, either directly or supported by coordinate indications obtained from one or two separate runs on 1-d projection(s). By-passing the “
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::661932e962ec9f9948b93f5565817934
https://doi.org/10.1515/zkri-2013-1723
https://doi.org/10.1515/zkri-2013-1723
Autor:
Armin Kirfel, Karl F. Fischer
Publikováno v:
Zeitschrift für Kristallographie. 225:261-273
A method for locating in an unknown one-dimensional structure (or structure projection) a resonant scattering atom from reflection intensities measured at two wavelengths is presented in terms of the parameter space concept. Even with rather few one-
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::60aa7e948da8eef88be725085b6454b0
https://doi.org/10.1524/zkri.2010.1241
https://doi.org/10.1524/zkri.2010.1241
Autor:
Armin Kirfel, Karl F. Fischer
Publikováno v:
Zeitschrift für Kristallographie. 224:325-339
For a centric crystal structure represented by m equal point scatterers at rest, absolute scaling of a small number n of reflection data reduced to relative geometrical structure amplitudes g′( h ) = K · |∑ cos (2πi hr j )|, j = 1, …, m; K =
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::073f25e85993e2eedc947c36a2f966d0
https://doi.org/10.1524/zkri.2009.1130
https://doi.org/10.1524/zkri.2009.1130
Publikováno v:
Zeitschrift für Kristallographie - Crystalline Materials. 221:673-680
Using for a one-dimensional centrosymmetric structure of m equal point scatterers an m-dimensional coordinate parameter space P m and the (n – 1) independent ratios q(h, k) = [I′(h)/I′(k)]1/2 = g′(h)/g′(k) of n > 1 structure amplitudes obse
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::716f8a9d9416d7293d7d27779c980170
https://doi.org/10.1524/zkri.2006.221.10.673
https://doi.org/10.1524/zkri.2006.221.10.673
Publikováno v:
Zeitschrift für Kristallographie - Crystalline Materials. 220:643-656
A concept is presented for determining a one-dimensional structure ofmindependent point scatterers by mapping into anm-dimensional spacePmat leastmobservations as (m– 1)-dimensional so-called “isosurfaces” defined bys(h) ·g(h) org(h) alone, wh
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::35d66be53e536c78df67148b574d2d27
https://doi.org/10.1524/zkri.220.7.643.67099
https://doi.org/10.1524/zkri.220.7.643.67099
Publikováno v:
Acta Crystallographica Section B Structural Science. 54:524-530
By taking into account the effects of domain structures and X-ray absorption, the superstructure of PbZrO3, lead zirconate, has been determined at room temperature. The space group is Pbam with a unit cell of a = 5.8884 (19), b = 11.771 (4) and c = 8
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2c4b69f3a9250d89e9a4340a3b14fd79
https://doi.org/10.1107/s0108768197018466
https://doi.org/10.1107/s0108768197018466
Publikováno v:
Journal of Applied Crystallography. 31:94-97
The first experimental evidence for orientational dispersion of an absorption tensor in the X-ray regime is presented. For two amphibole minerals, edenite and hastingsite, the X-ray absorption tensors were determined at the Fe K edge by means of pola
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f25277be92adf4bf1651c899fadb6668
https://doi.org/10.1107/s0021889897008790
https://doi.org/10.1107/s0021889897008790
Autor:
Karl F. Fischer, Katrin Pilz
Publikováno v:
Acta Crystallographica Section A Foundations of Crystallography. 53:475-483
A sequence of steps for determining a crystal structure, possibly without ambiguities, is presented. The prerequisites are: centrosymmetry (at present) and two different anomalous scatterers, a1, a2. Their partial structure amplitudes |Fa1(hkl)| and
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::031134f5ea6f3891cf785b16fe8ac08a
https://doi.org/10.1107/s0108767397003474
https://doi.org/10.1107/s0108767397003474
Publikováno v:
Acta Crystallographica Section B Structural Science. 53:415-419
Intensity measurements of several superlattice reflections of lead zirconate, PbZrO3, have been made on single-crystal specimens as a function of incident X-ray energy around the Pb L III and Zr K absorption edges. Anomalies in the squared structure
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ba0f7d7049b15ac8fbf4bade6813ac3c
https://doi.org/10.1107/s0108768197002759
https://doi.org/10.1107/s0108768197002759