Catalogo Articoli (Spogli Riviste)

OPAC HELP

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, B-2610 Wilrijk, Belgium Univ Instelling Antwerp Wilrijk Belgium B-2610 , B-2610 Wilrijk, Belgium Univ Antwerp, RUCA, Lab Anorgan Scheikunde, B-2020 Antwerp, Belgium Univ Antwerp Antwerp Belgium B-2020 Scheikunde, B-2020 Antwerp, Belgium
Titolo Testata:
ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE
, volume: 54, anno: 1998,
parte:, 6
pagine: 851 - 858
SICI:
0108-7681(199812)54:<851:NIAITA>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
MOLECULAR-STRUCTURE; 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, B-2610 Wilrijk, Be Univ Instelling Antwerp Univ Plein 1 Wilrijk Belgium B-2610
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. 851-858

Abstract

2,3-Diketopiperazine (2,3-piperazinedione), 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, D-x = 1.536 Mg m(-3) and M-r = 114.1. The six-membered ring adopts a skew-boat conformation with Q = 0.467 (3) Angstrom, theta = 64.6(3)degrees and phi = 269.8 (4)degrees. The C-2 symmetry, which typifies the free molecule, is broken by the formation of two intermolecular N-H O bonds involving only one of the C=O groups of the 2,3-diketopiperazine molecule. The intensity data typical for a time series are summarized in traditional statistics by B= sigma(2)(B) = Sigma B-i 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