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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A Diarylethene with Two Nitronyl Nitroxides: Photoswitching of Intramolecular Magnetic Interaction
Kenji Matsuda and,Masahiro Irie +1 more
TL;DR: A diarylethene having two nitronyl nitroxides, 1,2-bis[6-(1-oxyl-3oxide-4,4,5,5-tetramethylimidazolin-2-yl)-2-methyl-1-benzothiophen-3-yl]hexafluorocyclopentene (2a), was synthesized in an attempt to control the intramolecular magnetic interaction by photoirradiation as mentioned in this paper.
Journal ArticleDOI
Face-directed self-assembly of an electronically active Archimedean polyoxometalate architecture
TL;DR: It is shown that the face-directed assembly of a ring-shaped macrocyclic polyoxometalate structural building unit with an integrated 1-nm pore as an 'aperture synthon', with manganese linkers yields a vast three-dimensional extended framework architecture based on a truncated cuboctahedron.
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A left-hand beta-helix revealed by the crystal structure of a carbonic anhydrase from the archaeon Methanosarcina thermophila.
TL;DR: The structure of this carbonic anhydrase from the thermophilic archaeon Methanosarcina thermophila is presented, which adopts a left‐handed parallel beta‐helix fold and is suggestive of convergent evolution dictated by the chemical requirements for catalysis of the same reaction.
Journal ArticleDOI
A redox-active two-dimensional coordination polymer: preparation of silver and gold nanoparticles and crystal dynamics on guest removal.
TL;DR: The X-ray crystal structure of 2 reveals extensive dynamic motions of the molecular components in response to guest removal, involving rotation of the carboxylate and macrocycle, swing of the biphenyl, and bending of the macrocyclic coordination plane toward the car boxylate plane, which reduces the interlayer distance.
Journal ArticleDOI
Crystal structure of thermostable family 5 endocellulase E1 from Acidothermus cellulolyticus in complex with cellotetraose.
TL;DR: Structural comparisons show that all eight residues conserved in family 5 have functional equivalents in the other 4/7 superfamily members, strengthening the case that mechanistic details are conserved throughout the superfamily.
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.