Journal ArticleDOI
Phase annealing in SHELX-90: direct methods for larger structures
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TLDR
In this article, a phase annealing method, related to the simulated-annealing approach in other optimization problems, is proposed and it is shown that it can result in an improvement of up to an order of magnitude in the chances of solving large structures at atomic resolution.Abstract:
A number of extensions to the multisolution approach to the crystallographic phase problem are discussed in which the negative quartet relations play an important role. A phase annealing method, related to the simulated annealing approach in other optimization problems, is proposed and it is shown that it can result in an improvement of up to an order of magnitude in the chances of solving large structures at atomic resolution. The ideas presented here are incorporated in the program system SHELX-90; the philosophical and mathematical background to the direct-methods part (SHELXS) of this system is described.read more
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Antisymmetric exchange in two tricopper(II) complexes containing a [Cu3(μ3-OMe)]5+ core
TL;DR: These are the first examples of triangular Cu(II) compounds bearing a [Cu3micro3-OR)]5+(R is not equal to H) core motif, and the first triangular compounds showing antisymmetric exchange to have been analysed by both susceptibility and EPR measurements.
Journal ArticleDOI
Crystal structures and spectroscopic behavior of monomeric, dimeric and polymeric copper(II) chloroacetate adducts with isonicotinamide, N-methylnicotinamide and N,N-diethylnicotinamide
Ján Moncol,Marcela Mudra,Peter Lönnecke,Mark Hewitt,Marian Valko,Harry Morris,Jozef Švorec,Milan Melnik,Milan Mazúr,Marian Koman +9 more
TL;DR: In this paper, the crystal structures and spectroscopic properties of monomeric, dimeric and polymeric copper(II) chloroacetates with isonicotinamide (INA), N-methylnicotinamide(MNA), and N,N-diethylnicotine (DENA) were characterized by electron paramagnetic resonance (EPR) and IR spectroscopy.
Journal ArticleDOI
Cytotoxic flavonoids and alpha-pyrones from Cryptocarya obovata.
Vincent Dumontet,Nguyen Van Hung,Marie-Thérèse Adeline,Claude Riche,Angèle Chiaroni,Thierry Sévenet,Françoise Guéritte +6 more
TL;DR: One α-pyrone, obolactone (1), two chalcones, kurzichalcolactone B (2), and two flavanones, oboflavanones A (4) and B (5) have been isolated from the fruits and the trunk bark of Cryptocarya obovata as mentioned in this paper.
Journal ArticleDOI
Heterodinuclear Macrocyclic Complexes Containing Both Nickel(II) and Lanthanide(III) Ions.
TL;DR: The analysis of isotropic shifts of paramagnetic [LnNiL]Cl3 complexes shows the importance of both contact and dipolar contributions.
Journal ArticleDOI
Crystal Structure of a Viral FLIP INSIGHTS INTO FLIP-MEDIATED INHIBITION OF DEATH RECEPTOR SIGNALING
TL;DR: A high resolution crystal structure of MC159 is reported, a v-FLIP derived from the molluscum contagiosum virus, which is a member of the human poxvirus family, and its two tandem death effector domains rigidly associate with each other through a hydrophobic interface, suggesting a mechanism by which v- FLIP and c-FLIPS inhibit death receptor signaling.
References
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Book
Crystallographic Computing 3: Data Collection, Structure Determination, Proteins and Databases
TL;DR: The latest in a series on crystallographic computing, this collection of 33 papers covers the full spectrum of computer applications in crystallography, including the use of micro-, mini-, and mainframe computers.