XeOF5−, an Anion with Pentagonal-Pyramidal Structure

1995 ◽  
Vol 34 (15) ◽  
pp. 1586-1587 ◽  
Author(s):  
Arkady Ellern ◽  
Konard Seppelt
Keyword(s):  
Pyramidal Structure

scholarly journals Nanofocusing of surface plasmon polaritons by a pyramidal structure on an aperture

2010 ◽  
Vol 18 (2) ◽  
pp. 787 ◽  
Author(s):  
Kazuo Tanaka ◽  
Kiyofumi Katayama ◽  
Masahiro Tanaka
Keyword(s):  
Surface Plasmon ◽  
Surface Plasmon Polaritons ◽  
Pyramidal Structure ◽  
Plasmon Polaritons

scholarly journals An Unknown Force Awakened by A Pyramidal Structure

2016 ◽  
Vol 2 (06) ◽  
pp. 45-56
Author(s):  
Osamu Takagi
Keyword(s):  
Pyramidal Structure

New World Origins

Antiquity ◽  
1940 ◽  
Vol 14 (54) ◽  
pp. 117-137 ◽  
Author(s):  
J. Grahame D. Clark
Keyword(s):  
New World ◽  
Western Hemisphere ◽  
World Culture ◽  
Pyramidal Structure ◽  
Broad Base ◽  
Middle America ◽  
The Way

The dictum of Clark Wissler that ‘New World culture is [thus] a kind of pyramid whose base is as broad as the two Americas and whose apex rests over Middle America’ is one of those brilliant generalizations which at once sum up the conclusions already reached, and point the way to further progress.From the vantage of today one may agree with A. V. Kidder (22, p. 145) that American archaeologists have been unduly neglectful of the broad base of their pyramid. Yet itwould be churlish to blame them when the apex was so enticing, so rich, so bizarre and above all so enigmatic. Indeed, when men first descried the peaks of Maya, Mexican and Peruvian achievement, it seemed hard to connect them with the lowly foot- hills of cultural attainment familiar in the temperate latitudes of the western hemisphere. Until the underlying unity of civilization in the New World was recognized, its pyramidal structure could hardly be appreciated; in default of this it is easy to understand how archaeologists tended to neglect cultures, which, however interesting they may appear to us from the historical angle, must have appeared to them as intrinsically poor and dull. Then again it was only on the edges of the pyramid that the foundation layer was visible; elsewhere it was buried under a superstructure, massive in proportion to its attractiveness.

Study on the solar energy absorption of hybrid solar cells with trapezoid-pyramidal structure based PEDOT:PSS/c-Ge

Solar Energy ◽  
2020 ◽  
Vol 204 ◽  
pp. 635-643 ◽  
Author(s):  
Fei Zhao ◽  
Xifang Chen ◽  
Zao Yi ◽  
Feng Qin ◽  
Yongjian Tang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Energy ◽  
Energy Absorption ◽  
Hybrid Solar Cells ◽  
Pyramidal Structure

Are Tetra[gold(I)]phosphonium Cations [(LAu)4P]+ Non-obedient to the LeBel-van’t Hoff Rule?

2008 ◽  
Vol 63 (7) ◽  
pp. 853-859 ◽  
Author(s):  
Hubert Schmidbaur
Keyword(s):  
Ground State ◽  
Central Element ◽  
Theoretical Studies ◽  
Tetrahedral Structure ◽  
Pyramidal Structure ◽  
Onium Salts ◽  
Central Elements ◽  
Aurophilic Interactions ◽  
Molecular And Electronic Structure ◽  
Phosphonium Cations

Recent theoretical studies of the molecular and electronic structure of tetra[(phosphine)gold(I)]- phosphonium cations, [(H3PAu)4P]+, gave contradictory results favoring either a classical tetrahedral or a unique square-pyramidal structure of the PAu4 unit. A tetrahedral structure had previously been confirmed for the corresponding ammonium cations [(Ph3PAu)4N]+, while a square-pyramidal structure was discovered for the corresponding arsonium cations [(Ph3PAu)4As]+, but there is as yet no unequivocal experimental evidence for the structure of phosphonium cations like [(Ph3PAu)4P]+ in an innocent environment. - In this account the structural chemistry of this class of onium salts and related species is reviewed. The data accumulated to date provide virtually compelling evidence that the phosphonium cations should have a ground state with a square pyramidal PAu4 core unit, provided that no external constraints are imposed. For large central elements (P, As), aurophilic interactions appear to drive the reorganization from tetrahedral to square-pyramidal skeletons in which a maximum number of short Au---Au contacts can be maintained. For the small central element N, similar interactions are already realized in the tetrahedral structure.

The Crystal Structure of Solvated Molybdenum Oxide Tetrachloride

1981 ◽  
Vol 36 (11) ◽  
pp. 1416-1418 ◽  
Author(s):  
Mary Mercer ◽  
Kenneth W. Muir ◽  
David W. A. Sharp
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Molybdenum Oxide ◽  
Pyramidal Structure

Abstract MoOCl4 in the solid state has a square pyramidal structure with chlorine-bridging trans to the oxygen linking the molecules into infinite chains. The structure gives holes in the lattice occupied by solvate molecules.

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