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Titolo: Net intensities: Accuracy improvement through a Bayesian perspective on the measuring strategy and their persistent lack of precision. An illustration
Autore: Lenstra, ATH; Bracke, B; van Dijk, B; Maes, S; Vanhulle, C; Desseyn, HO;
 Indirizzi:
 Univ Instelling Antwerp, Dept Struct Chem, B2610 Wilrijk, Belgium Univ Instelling Antwerp Wilrijk Belgium B2610 , B2610 Wilrijk, Belgium Univ Antwerp, RUCA, Lab Anorgan Scheikunde, B2020 Antwerp, Belgium Univ Antwerp Antwerp Belgium B2020 Scheikunde, B2020 Antwerp, Belgium
 Titolo Testata:
 ACTA CRYSTALLOGRAPHICA SECTION BSTRUCTURAL SCIENCE
,
volume: 54,
anno: 1998,
parte:, 6
pagine: 851  858
 SICI:
 01087681(199812)54:<851:NIAITA>2.0.ZU;2N
 Fonte:
 ISI
 Lingua:
 ENG
 Soggetto:
 MOLECULARSTRUCTURE; DIFFRACTION; DIHYDRATE; ACETAMIDE; ABINITIO;
 Tipo documento:
 Article
 Natura:
 Periodico
 Settore Disciplinare:
 Physical, Chemical & Earth Sciences
 Citazioni:
 16
 Recensione:
 Indirizzi per estratti:
 Indirizzo: Lenstra, ATH Univlgiumelling Antwerp, Dept Struct Chem, Univ Plein 1, B2610 Wilrijk, Be Univ Instelling Antwerp Univ Plein 1 Wilrijk Belgium B2610



 Citazione:
 A.T.H. Lenstra et al., "Net intensities: Accuracy improvement through a Bayesian perspective on the measuring strategy and their persistent lack of precision. An illustration", ACT CRYST B, 54, 1998, pp. 851858
Abstract
2,3Diketopiperazine (2,3piperazinedione), C4H6N2O2, crystallizes in the monoclinic space group P2(1)/c with a = 5.941 (3), b = 10.080 (3), c = 8.282 (2) Angstrom, beta = 95.57 (3)degrees, V = 493.4 (5) Angstrom(3), Z = 4, Dx = 1.536 Mg m(3) and Mr = 114.1. The sixmembered ring adopts a skewboat conformation with Q = 0.467 (3) Angstrom, theta = 64.6(3)degrees and phi = 269.8 (4)degrees. The C2 symmetry, which typifies the free molecule, is broken by the formation of two intermolecular NH O bonds involving only one of the C=O groups of the 2,3diketopiperazine molecule. The intensity data typical for a time series are summarized in traditional statistics by B= sigma(2)(B) = Sigma Bi and R = sigma(2)(R) = CR,, where B is the background and R the raw intensity. Exploitation of the same data using Bayesian methodology leads to similar values for B and R, but the variances for these signals are significantly smaller. This reduction in variance is dictatedby the length N of the time series. With 25 observations in each hkl time series we arrive at variances that are 25% of their classical values. So, ameasuring strategy in which a single similar to 2% of the maximum Bragg intensity found at lambda 0.71 Angstrom.
ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 23/11/20 alle ore 20:14:02