Electronic structure analysis of intermetallics for crystal structure changes in Nb3Al

1994 ◽  
Vol 2 (3) ◽  
pp. 363-370 ◽  
Author(s):  
S Ito ◽  
T Fujiwara
1997 ◽  
Vol 52 (11) ◽  
pp. 1315-1320 ◽  
Author(s):  
Andreas Madema ◽  
Hans Pritzkow ◽  
Walter Siebert ◽  
Thomas Sommerfeld ◽  
Lorenz S. Cederbaum

The synthesis and properties of donor-stabilized trisethinylborane compounds 1 - 3 (donor = pyridine, tetrahydrothiophene, tetrahydrofuran) and of the tris(trimethylsilylethinyl)boranediethylether adduct 4 are reported. Attempts to obtain donor-free trisorganylethinylboranes have failed. 11B NMR data of 1 - 4 and the X-ray structure analysis of 1 and 3 reveal that the boron atoms are four-coordinated. The B-C bonds in 1 are somewhat longer and the C≡C bonds shorter than in diborylacetylenes.


1993 ◽  
Vol 329 ◽  
Author(s):  
Vivien D.

AbstractIn this paper the relationships between the crystal structure, chemical composition and electronic structure of laser materials, and their optical properties are discussed. A brief description is given of the different laser activators and of the influence of the matrix on laser characteristics in terms of crystal field strength, symmetry, covalency and phonon frequencies. The last part of the paper lays emphasis on the means to optimize the matrix-activator properties such as control of the oxidation state and site occupancy of the activator and influence of its concentration.


Author(s):  
M. Bidya Sagar ◽  
K. Ravikumar ◽  
Y. S. Sadanandam

AbstractThe crystallographic characterization of the following three calcium channel antagonists is reported here: 2,6-dimethyl-3,5-dicarbamoyl-4-[2-nitro]-1,4-dihydropyridine (


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 734
Author(s):  
Aija Trimdale ◽  
Anatoly Mishnev ◽  
Agris Bērziņš

The arrangement of hydroxyl groups in the benzene ring has a significant effect on the propensity of dihydroxybenzoic acids (diOHBAs) to form different solid phases when crystallized from solution. All six diOHBAs were categorized into distinctive groups according to the solid phases obtained when crystallized from selected solvents. A combined study using crystal structure and molecule electrostatic potential surface analysis, as well as an exploration of molecular association in solution using spectroscopic methods and molecular dynamics simulations were used to determine the possible mechanism of how the location of the phenolic hydroxyl groups affect the diversity of solid phases formed by the diOHBAs. The crystal structure analysis showed that classical carboxylic acid homodimers and ring-like hydrogen bond motifs consisting of six diOHBA molecules are prominently present in almost all analyzed crystal structures. Both experimental spectroscopic investigations and molecular dynamics simulations indicated that the extent of intramolecular bonding between carboxyl and hydroxyl groups in solution has the most significant impact on the solid phases formed by the diOHBAs. Additionally, the extent of hydrogen bonding with solvent molecules and the mean lifetime of solute–solvent associates formed by diOHBAs and 2-propanol were also investigated.


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