Dodecahedron- and Bowl-Shaped Structures C20

1992 ◽  
Vol 270 ◽  
Author(s):  
Zdenék Slanina ◽  
Ludwik Adamowicz
Keyword(s):  
High Temperature ◽  
Temperature Region ◽  
Relative Stability ◽  
Three Dimensional ◽  
Two Dimensional ◽  
High Temperature Region ◽  
Relative Stabilities ◽  
One Dimensional ◽  
Very High ◽  
Quantumchemical Method

ABSTRACTPurely carbonaceous aggregates C20 have been studied by the AM1 quantumchemical method. In addition to one dodecahedron-shaped structure possessing C1 symmetry another three-dimensional species is revealed, viz. a bowl-shaped structureof C5v symmetry (and also one two-dimensional and two one-dimensional species). Temperature dependence of the relative stabilities of both three-dimensional structures is evaluated, showing that in the relevant temperature region the fullerenic species is prevailing. However, in a very high temperature region a relative-stability interchange has been predicted.

Observation of hysteretic magnetic phase transitions coupled with orientation motion of ions and dielectric relaxation in a one-dimensional nickel-bis-dithiolene molecule solid

2014 ◽  
Vol 43 (16) ◽  
pp. 6251-6261 ◽  
Author(s):  
Xuan-Rong Chen ◽  
Wei-Hua Ning ◽  
Hao Yang ◽  
Jian-Lan Liu ◽  
Fang Xuan ◽  
...  
Keyword(s):  
Phase Transitions ◽  
High Temperature ◽  
Dielectric Relaxation ◽  
Temperature Region ◽  
Magnetic Phase ◽  
Magnetic Transition ◽  
Magnetic Phase Transitions ◽  
Structural Transitions ◽  
High Temperature Region ◽  
One Dimensional

Step-wise orientation motions of ions results in two successive structural transitions, each one is associated with a hysteretic magnetic transition and dielectric relaxation occurs in the high temperature region.

The purine–carboxylate-containing coordination polymer poly[[μ4-1-(2-carboxylatoethyl)-6-oxo-6,9-dihydro-1H-purin-9-ido]zinc(II)]

2013 ◽  
Vol 69 (11) ◽  
pp. 1314-1316
Author(s):  
Wen-Juan Ma ◽  
Guo-Ting Li
Keyword(s):  
Thermal Stability ◽  
Coordination Polymer ◽  
Title Compound ◽  
Topological Structure ◽  
Three Dimensional ◽  
Two Dimensional ◽  
One Dimensional ◽  
Metal Organic ◽  
Very High ◽  
Thermal Stability Of

The title compound, [Zn(C8H6N4O3)]nor [Zn(L)]n[H2Lis 3-(6-oxo-6,9-dihydro-1H-purin-1-yl)propionic acid], crystallized as a nonmerohedral twin. The ZnIIcation is four-coordinated, ligated by two carboxylate O atoms from twoLligands and two N atoms from another two ligands. Each ligand bridges four ZnIIcentres, extending the structure into a three-dimensional polymer with a 4-connected (65,41) topological structure containing two-dimensional homochiral layers constructed from one-dimensional metal–organic helices. Investigation of the thermal stability of the compound shows that the network has very high thermostability and is stable up to 720 K.

Surface Structure and Growth Mode of Pd Deposited on Mo(110) Surface

2003 ◽  
Vol 10 (02n03) ◽  
pp. 425-430 ◽  
Author(s):  
Y. Maehara ◽  
H. Kawanowa ◽  
Y. Gotoh
Keyword(s):  
High Temperature ◽  
Surface Structure ◽  
Temperature Region ◽  
Coincident Site Lattice ◽  
High Energy ◽  
Growth Mode ◽  
Ordered Structure ◽  
High Temperature Region ◽  
One Dimensional ◽  
Dimensional Growth

The surface structure and growth mode of Pd/Mo(110) have been studied using reflection high energy electron diffraction (RHEED). The surface diagram of Pd on the Mo(110) substrate for deposition thickness versus substrate temperature was obtained. Four kinds of surface structures, namely α1, α2, β and γ, were observed. At less than 1 ML, α2 appeared in temperatures ranging from 400 to 1050°C and α1 appeared from RT to 400°C. α2 has a structure intermediate between those of Pd(111) and Mo(110), in which the dense direction of the layer is parallel to the [111]Mo orientation and their atomic row distances are coincident, resulting in formation of a long-period structure with a Mo surface, namely a coincident site lattice. The α1 structure is similar to the 1 × 1 structure. At more than 1.0 ML, β and γ structures appeared simultaneously in the temperature region from 500 to 950°C. However, at a high temperature region from 950 to 1050°C, the α2 structure was observed. β shows a one-dimensional ordered structure, in which Pd atoms line along [111]Mo. γ exhibits a 3 × 1 structure with the same atomic arrangement as the Mo(110) plane rotated at 70.5°. At greater than 2.0 ML, the Pd film grows in the Frank–van der Merwe growth mode at a low temperature with accumulation of a Pd(111) layer, and in the Stranski–Krastanov growth mode at a high temperature with two-dimensional growth of the γ structure followed by formation of flat crystallites.

Transformations of two-dimensional layered zinc phosphates to three-dimensional and one-dimensional structures

2002 ◽  
Vol 12 (4) ◽  
pp. 1044-1052 ◽  
Author(s):  
Amitava Choudhury ◽  
S. Neeraj ◽  
Srinivasan Natarajan ◽  
C. N. R. Rao
Keyword(s):  
Three Dimensional ◽  
Two Dimensional ◽  
One Dimensional ◽  
Zinc Phosphates

Mine Impact Burial Prediction From One to Three Dimensions

2008 ◽  
Vol 62 (1) ◽  
Author(s):  
Peter C. Chu
Keyword(s):  
Three Dimensional ◽  
Time History ◽  
Three Dimensions ◽  
Vertical Position ◽  
Burial Depth ◽  
Prediction Errors ◽  
Two Dimensional ◽  
Dimensional Model ◽  
One Dimensional ◽  
Dimensional Models

The Navy’s mine impact burial prediction model creates a time history of a cylindrical or a noncylindrical mine as it falls through air, water, and sediment. The output of the model is the predicted mine trajectory in air and water columns, burial depth/orientation in sediment, as well as height, area, and volume protruding. Model inputs consist of parameters of environment, mine characteristics, and initial release. This paper reviews near three decades’ effort on model development from one to three dimensions: (1) one-dimensional models predict the vertical position of the mine’s center of mass (COM) with the assumption of constant falling angle, (2) two-dimensional models predict the COM position in the (x,z) plane and the rotation around the y-axis, and (3) three-dimensional models predict the COM position in the (x,y,z) space and the rotation around the x-, y-, and z-axes. These models are verified using the data collected from mine impact burial experiments. The one-dimensional model only solves one momentum equation (in the z-direction). It cannot predict the mine trajectory and burial depth well. The two-dimensional model restricts the mine motion in the (x,z) plane (which requires motionless for the environmental fluids) and uses incorrect drag coefficients and inaccurate sediment dynamics. The prediction errors are large in the mine trajectory and burial depth prediction (six to ten times larger than the observed depth in sand bottom of the Monterey Bay). The three-dimensional model predicts the trajectory and burial depth relatively well for cylindrical, near-cylindrical mines, and operational mines such as Manta and Rockan mines.

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