Bernstein's bond length-bond order relation is applied to carbon-nitrogden, carbon-oxygen, and nitrogen-oxygen bonds in metal complexes

1968 ◽  
Vol 7 (1) ◽  
pp. 181-182 ◽  
Author(s):  
John P. Fackler ◽  
Dimitri Coucouvanis
1989 ◽  
Vol 67 (11) ◽  
pp. 1975-1979 ◽  
Author(s):  
Y. K. Wu ◽  
K. A. R. Mitchell

A new intensity analysis with low-energy electron diffraction is reported for the (2 × 2) surface structure obtained by the adsorption of H2S on the (111) surface of nickel. Intensity-versus-energy curves were measured with a video LEED analyzer for 10 diffracted beams at normal incidence, and comparisons were made with intensity curves calculated with multiple-scattering methods for models in which S atoms chemisorb at three-fold coordinated adsorption sites, but with the possibilities of both lateral and vertical relaxations in the local metallic structure. Small adsorbate-induced relaxations are found, but the dominant structural feature is that the S atoms adsorb above the "expected" adsorption sites (i.e. those which continue the regular fee packing) with a 1.50 Å spacing between the S layer and the top-most Ni layer. The S–Ni bond length of 2.10 Å agrees to within 0.02 Å of a prediction using a current bond length – bond order relation, but this value is smaller than two other recent measurements by SEXAFS and ion scattering by 0.06 and 0.10 Å, respectively. This analysis also finds the first two Ni layer spacings are expanded from the bulk value by 2 to 3%. Keywords: LEED, surface structure, S chemisorption, Ni(III) surface.


1957 ◽  
Vol 30 (6) ◽  
pp. 638-647 ◽  
Author(s):  
Tosinobu Anno ◽  
Mitsuo Ito ◽  
Ryoichi Shimada ◽  
Akira Sado ◽  
Wataru Mizushima

1983 ◽  
Vol 36 (4) ◽  
pp. 639 ◽  
Author(s):  
RD Brown ◽  
PD Godfry ◽  
BT Hart ◽  
AL Ottrey ◽  
M Onda ◽  
...  

The microwave spectrum of the benzene isomer 3,4-dimethylenecyclobutene including spectra of all possible single 13C-substituted and sufficient singly and doubly D-substituted species to give a complete r5 geometry, have been measured and analysed. An estimate of the re geometry has also been derived. The additional precise CC bond lengths obtained for an unsubstituted, conjugated hydrocarbon enable us to examine bond order-bond length relationships more thoroughly than has previously been possible. The CC bond lengths exhibit a noticeably better correlation with SCFMO bond orders than with simple H�ckel bond orders. Further confirmatory measurements of the dipole moment of dimethylenecyclobutene have been made. Ab initio molecular orbital calculations using a 6-31G basis set give an optimized geometry with CC bond lengths within 2 pm of the r5 values. The computed dipole moment agrees almost exactly with experiment but a corresponding calculation on fulvene is discrepant with experiment by 0.16 D, which is probably a more typical error.


1996 ◽  
Vol 65 (6) ◽  
pp. 1641-1647 ◽  
Author(s):  
Kei Odai ◽  
Hideki Ono ◽  
Hideo Suzuki
Keyword(s):  

2003 ◽  
Vol 68 (2) ◽  
pp. 307-330 ◽  
Author(s):  
Antonio Laganà ◽  
Stefano Crocchianti ◽  
Noelia Faginas Lago ◽  
Leonardo Pacifici ◽  
Gianni Ferraro

Computational approaches to the evaluation of the reactive scattering properties of atom- diatom reactions are revisited. The aim is to exploit both the use of nonorthogonal coordinates in reactive scattering and the restructuring of related computer codes for concurrent computing. To this end, bond length, bond-order and hyperspherical bond order coordinate formalisms are examined for the collinear case. At the same time, the evolution of parallel models from coarse to fine granularity and the development of parallelization supports from directive libraries to programming environments are discussed. The scalability of related codes is tested by measuring the performances of restructured codes. The suitability of the use of nonorthogonal coordinates for scattering purposes is tested by performing collinear calculations for the H + H2 reaction.


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