Hexakis(acetato)oxotetrazinc, a well-tailored molecular model of zinc oxide. An experimental and theoretical investigation of the electronic structure of Zn4O(acetate)6 and ZnO by means of UV and x-ray photoelectron spectroscopies and first principle local density molecular cluster calculations

1992 ◽  
Vol 31 (9) ◽  
pp. 1558-1565 ◽  
Author(s):  
Renzo Bertoncello ◽  
Marco Bettinelli ◽  
Maurizio Casarin ◽  
Antonino Gulino ◽  
Eugenio Tondello ◽  
...  
1992 ◽  
Vol 270 ◽  
Author(s):  
Arne RosÉn ◽  
Daniel Östling

ABSTRACTMolecular cluster calculations within the local density approximation have been performed in a study of the electronic structure of the C60 molecule - “Buckminsterfullerene” doped with K, B and N. Calculations for the KC60 molecule, with the K atom located at the centre of the cage as well as at different positions inside or outside the cage, show how the valence 4s electron is transferred to the LUMO state of the bare C60 molecule. Doping with a B or N atom located at the centre of the cage creates a molecule with a partly occupied level of 2p character in the HOMO and LUMO gap, similar to donor and acceptor levels in the band gap of traditionally doped semiconductors. Doping by substitution of one or two of the carbon atoms in the cage with X = B or N, as modelled with the C59 X1 or C58X2 clusters, gives a different structure with a splitting of the HOMO and LUMO levels in the pure C60 molecule and with the creation of acceptor and donor levels with the substitution of B and N, respectively.


Author(s):  
Chunhai Lu ◽  
Wenkai Chen ◽  
Min Chen ◽  
Shijun Ni ◽  
Chengjiang Zhang

The local-density approximation (LDA) coupled with the virtual crystal approximation (VCA) method electronic structure is applied to evaluate elastic constants, bulk modulus, shear modulus, Young’s modulus and Poisson’s ratio mechanic properties of metal zirconium, Zircaloy-2 and Zircaloy-4. The results show that there is no obvious difference in band structure and total density of state (DOS) between metal zirconium and zirconium alloy. However, p and d electron partial density of state (PDOS) presents the slight difference between metal zirconium and zirconium alloy. Zircaloy-2 and Zircaloy-4 present better elastic mechanical properties than metal zirconium. The metal zirconium and zirconium alloy show the anisotropic mechanical properties.


1989 ◽  
Vol 114 ◽  
pp. 495-497 ◽  
Author(s):  
E.P. Domashevskaya ◽  
Yu.K. Timoshenko ◽  
V.A. Terekhov ◽  
E.N. Desyatirikova ◽  
E.Yu. Bulycheva ◽  
...  

2007 ◽  
Vol 1048 ◽  
Author(s):  
Daisuke Fukamaki ◽  
Tsunehiro Takeuchi ◽  
Masashi Hasegawa ◽  
Kazuo Soda ◽  
Hirokazu Sato ◽  
...  

AbstractStability of Pd-Co-Ni-Cu-P metallic glass was investigated in terms of free energy using first principle cluster calculations, thermal analysis, and photoemission spectroscopy measurements. We found that the internal energy of the Pd-based metallic glasses is dominated by the electronic structure near the Fermi level. The analyses on the electronic structure and local atomic arrangements indicate that the substitution of cobalt or a hypothetical atom Co0.5Cu0.5 for nickel in the Pd40Ni40P20 metallic glass decreases the free energy of the Pd-Ni-P metallic glass by increasing entropy without altering significantly internal energy. On the basis of the idea mentioned above, we prepared Pd28Co24Ni24P24, Pd25Co25Ni25P25 and Pd40Co40/3Ni40/3Cu40/3P20 metallic glasses. These metallic glasses certainly showed the nearly highest TX, which directly reflect the activation energy against crystallization, among the Pd-based metallic glasses ever reported.


2006 ◽  
Vol 330 (1) ◽  
pp. 25-35 ◽  
Author(s):  
A. Audzijonis ◽  
L. Žigas ◽  
R. Žaltauskas ◽  
J. Narušis ◽  
A. Pauliukas ◽  
...  

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