A fast and exact algorithm to calculate the powder pair distribution function (PDF) for the case of periodic structures is presented. The new algorithm calculates the PDF by a detour via reciprocal space. The calculated normalized total powder diffraction pattern is transferred into the PDF via the sine Fourier transform. The calculation of the PDF via the powder pattern avoids the conventional simplification of X-ray and electron atomic form factors. It is thus exact for these types of radiation, as is the conventional calculation for the case of neutron diffraction. The new algorithm further improves the calculation speed. Additional advantages are the improved detection of errors in the primary data, the handling of preferred orientation, the ease of treatment of magnetic scattering and a large improvement to accommodate more complex instrumental resolution functions.
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http://dx.doi.org/10.1107/S1600576720004616 | DOI Listing |
Molecules
January 2025
Department of Chemistry, Hunter College, The City University of New York, 695 Park Ave., New York, NY 10065, USA.
Using methods of DFT, we investigated the effect of electron withdrawing and electron donating groups on the relative stability of tentative glycosyl donor reaction intermediates. The calculation shows that by changing the stereoelectronic properties of the protecting group, we can influence the stability of the dioxolenium type of intermediates by up to 10 kcal mol, and that by increasing nucleophillicity of the 4--Bz group, the dioxolenium intermediate becomes more stable than a triflate-donor pair. We exploited this mechanism to design galactosyl donors with custom protecting groups on O2 and O4, and investigated the outcome of the reaction with cyclohexanol.
View Article and Find Full Text PDFMolecules
January 2025
Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
The overexpression of the epidermal growth factor receptor (EGFR) in certain types of prostate cancers and glioblastoma makes it a promising target for targeted radioligand therapy. In this context, pairing an EGFR-targeting peptide with the emerging theranostic pair comprising the Auger electron emitter cobalt-58m (Co) and the Positron Emission Tomography-isotope cobalt-55 (Co) would be of great interest for creating novel radiopharmaceuticals for prostate cancer and glioblastoma theranostics. In this study, GE11 (YHWYGYTPQNVI) was investigated for its EGFR-targeting potential when conjugated using click chemistry to N1-((triazol-4-yl)methyl)-N1,N2,N2-tris(pyridin-2-ylmethyl)ethane-1,2-diamine (TZTPEN).
View Article and Find Full Text PDFActa Crystallogr B Struct Sci Cryst Eng Mater
February 2025
Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 2 Okólna, Wrocław, 50-422, Poland.
X-ray structural analysis of bis(guanidinium) disodium hypodiphosphate heptahydrate, (CHN)Na(PO)·7HO revealed close Na...
View Article and Find Full Text PDFRev Sci Instrum
January 2025
Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China.
In inertial confinement fusion experiments, hot spot mix caused by hydrodynamic instabilities is a critical performance limitation. Currently, multi-channel Ross filter pair imaging is used to quantitatively diagnose the mix mass of cryogenic hot spots driven by 100 kJ energy, but this method brings significant uncertainty. To measure the level of mix more accurately, we have developed a two-temperature model to modify the fitted bremsstrahlung spectra based on the characteristics of cryogenic implosion hot spots.
View Article and Find Full Text PDFJ Imaging
January 2025
State Key Laboratory of Power Transmission Equipment Technology, School of Electrical Engineering, Chongqing University, Chongqing 400044, China.
In grid intelligent inspection systems, automatic registration of infrared and visible light images in power scenes is a crucial research technology. Since there are obvious differences in key attributes between visible and infrared images, direct alignment is often difficult to achieve the expected results. To overcome the high difficulty of aligning infrared and visible light images, an image alignment method is proposed in this paper.
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