Pearson's crystal data: crystal structure database for inorganic compounds

Release 2002/2 of the Inorganic Crystal Structure Database (FIZ Karlsruhe, Germany, and Institute Laue–Langevin, Grenoble, France) contains 62 entries in space group P31 and ten entries in space group P32 for 49 different materials including eight families with two or more isostructural members. The structural criteria for ferroelectricity are satisfied for 16 new structure types at a confidence level that depends on the reliability of each determination. LaBGeO5, a mineral with stillwellite structure, was previously reported as ferroelectric and forms an additional family with seven other members or related structures that satisfy the criteria. Ten structures reported in space group P31 or P32 are dubious or incorrect, with atomic coordinates that satisfy supergroup symmetry. One material is probably pyroelectric but is unlikely to become ferroelectric, and three others are either incompletely solved or incompletely refined. Among the predicted new ferroelectrics are Cu2BaGeS4, Fe3(Fe,Si)O4(OH)5, Se4S5, K2HCr2AsO10, IV-RbNO3, Rb2Sc(NO3)5, Na3ReO5, Nd14(GeO4)2(BO3)6O8, CsHgCl3, Ba2Cu2AlF11, KYF4, SrS2O6·4H2O, Cu3PbTeO6(OH)2, ReH(CO)4, Ni2(NH3)9Mo(CN)8·2H2O and the 6T polytype of Ca1.89Ta1.80Sm0.16Ti0.10O7, in addition to β-LaBSiO5, PbBAsO5 and BaBAsO5 in the stillwellite family.

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Structural Variations of Single and Tandem Mismatches in RNA Duplexes: A Joint MD Simulation and Crystal Structure Database Analysis

The Journal of Physical Chemistry B ◽

10.1021/jp305628v ◽

2012 ◽

Vol 116 (39) ◽

pp. 11845-11856 ◽

Cited By ~ 12

Author(s):

Sukanya Halder ◽

Dhananjay Bhattacharyya

Keyword(s):

Crystal Structure ◽

Md Simulation ◽

Structural Variations ◽

Database Analysis ◽

Structure Database ◽

Rna Duplexes ◽

Crystal Structure Database

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Bond analyses of borates from the Inorganic Crystal Structure Database

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768106018520 ◽

2006 ◽

Vol 62 (5) ◽

pp. 702-709 ◽

Cited By ~ 37

Author(s):

Daqiu Yu ◽

Dongfeng Xue

Keyword(s):

Crystal Structure ◽

Building Blocks ◽

Low Complexity ◽

Bond Valence ◽

Inorganic Crystal Structure Database ◽

Bonding Structure ◽

Structural Evaluation ◽

Structure Database ◽

Inorganic Crystal ◽

Crystal Structure Database

Various fundamental building blocks (FBBs) are observed in the crystallographic structures of oxoborates available in the Inorganic Crystal Structure Database, Version 1.3.3 (2004); the occurrence of borate groups with low complexity is dominant. Bond-valence parameters d 0 of B—O bonds in 758 oxoborates with various FBBs have been calculated using the bond-valence sum model. Some discrepancies in the d 0 values obviously occur if the detailed configurations of FBBs in borate crystals are considered; d 0 is sensitive to the chemical bonding structure of B atoms in the crystallographic framework. Moreover, d 0 values are affected by the existence of interstitial atoms and the substitution of other anionic groups. In addition, the d 0 parameters for B—N, B—S, B—P and B—F bonds are also calculated statistically. Some suitable d 0 data for various borate FBBs are recommended according to their particular configurations, especially for those with low complexity. On the basis of the proposed linear relationship between calculated nonlinear optical (NLO) coefficients of borates and the current d 0 values for various FBBs, it is found that the d 0 values may be regarded as a useful parameter for pre-investigating the NLO properties of borates, leading to an efficient structural evaluation and design of novel borates.

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