Search results for " Structure"
showing 10 items of 25475 documents
Computing Subdivision Surface Intersection
2003
Computer surface intersections is fundamental problem in geometric modeling. Any Boolean operation can be seen as an intersection calculation followed by a selection of parts necessary for building the surface of the resulting object. This paper deals with the computing of intersection curveson subdivision surfaces (surfaces generated by the Loop scheme). We present three variants of our algorithm. The first variant calculates this intersection after classification of the object faces into intersecting and non-intersecting pairs of faces. the second variant is based on 1-neighborhood of the intersecting faces. The third variant uses the concept of bipartite graph.
Psychometric Evaluation of the Norwegian Versions of the Modified Group Environment Questionnaire and the Youth Sport Environment Questionnaire
2021
This study aimed to translate the modified Group Environment Questionnaire (GEQ) and the Youth Sport Environment Questionnaire (YSEQ) into Norwegian, examine the factor structure and reliability of the scales through independent clusters model confirmatory factor analysis (ICM-CFA) and exploratory structural equation modeling (ESEM), and examine differential item functioning (DIF) as a function of sex. Three-hundred-and-thirty-three athletes (M(SD)age = 18.7(2.60) years; 33% females) completed the GEQ. Three-hundred-and-three athletes (M(SD)age = 15.0(1.48) years; 26% females) completed the YSEQ. Results indicated acceptable fit indices for a four-factor, a second-order two-factor (task a…
Intramolecular Hydrogen Bond, Hirshfeld Analysis, AIM; DFT Studies of Pyran-2,4-dione Derivatives
2021
Intra and intermolecular interactions found in the developed crystals of the synthesized py-ron-2,4-dione derivatives play crucial rules in the molecular conformations and crystal stabili-ties, respectively. In this regard, Hirshfeld calculations were used to quantitatively analyze the different intermolecular interactions in the crystal structures of some functionalized py-ran-2,4-dione derivatives. The X-ray structure of pyran-2,4-dione derivative namely (3E,3′E)-3,3′-((ethane-1,2-diylbis(azanediyl))bis(phenylmethanylylidene))bis(6-phenyl-2H-pyran-2,4(3H)-dione) was determined. It crystallized in the monoclinic crystal system and C2/c space group with unit cell parameters: a = 14.0869(4) …
CCDC 1576743: Experimental Crystal Structure Determination
2019
Related Article: Arkalekha Mandal, Kari Rissanen, Prasenjit Mal|2019|CrystEngComm|21|4401|doi:10.1039/C9CE00561G
CCDC 1893191: Experimental Crystal Structure Determination
2019
Related Article: Esa Kukkonen, Henri Malinen, Matti Haukka, Jari Konu|2019|Cryst.Growth Des.|19|2434|doi:10.1021/acs.cgd.9b00119
(E)-1-(Pyridin-4-yl)propan-1-one oxime
2016
The asymmetric unit of the title compound, C8H10N2O, contains two crystallographically independent molecules of slightly different conformation, which are linkedviaan intermolecular O—H...N hydrogen bond. The dihedral angle between the pyridine ring and the oxime plane of moleculeA[2.09 (19)°] is smaller than in moleculeB[16.50 (18)°].
Poly[[tetramethanolbis[4-oxo-3-(pyridin-4-yl)-1-(2,4,6-trichlorophenyl)-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6-olato]disodium]–diethyl ether–metha…
2016
In the title compound, [Na2(C16H7Cl3N5O2)2(CH3OH)4]·C4H10O·2CH3OH, the central pyrazolo[3,4-d]pyrimidine system makes dihedral angles of 82.98 (7)° with the trichlorophenyl ring and 13.11 (15)° with the pyridine ring. The sodium ion has an octahedral environment, being coordinated by four methanol molecules and one O and one N atom of two different heterocyclic ring systems.
(E)-1-(Pyridin-4-yl)propan-1-one O-tosyl oxime
2017
The title compound, C15H16N2O3S, was obtained by the reaction of (E)-1-(pyridin-4-yl)propan-1-one oxime andpara-toluenesulfonic acid. The pyridine ring makes a dihedral angle of 54.70 (10)° with the benzene ring. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a chain along thec-axis direction.
Crystal structure of the pyridine–diiodine (1/1) adduct
2015
In the title adduct, C5H5N·I2, the N—I distance [2.424 (8) Å] is remarkably shorter than the sum of the van der Waals radii. The line through the I atoms forms an angle of 78.39 (16)° with the normal to the pyridine ring.
3-(2,4-Difluorophenyl)-1-(pyridin-4-yl)benzo[4,5]imidazo[1,2-d][1,2,4]triazin-4(3H)-one
2016
In the title compound, C20H11F2N5O, the central 13-membered ring system (r.m.s. deviation = 0.028 Å) makes a dihedral angle of 53.13 (7)° with the difluorophenyl ring and 79.98 (7)° with the pyridine ring. The crystal packing features aromatic π–π interactions between the 13-membered rings [shortest distance between ring centroids = 3.5682 (8) Å].