On the valences of bonds in the oxycomplexes of Sn2+

2009 ◽  
Vol 65 (6) ◽  
pp. 684-693 ◽  
Author(s):  
I. David Brown
Keyword(s):  
Valence Bond ◽  
Lone Pair ◽  
Bond Valence ◽  
Ionic Charge ◽  
Acta Cryst ◽  
Pair Bonds ◽  
The Standard Model ◽  
Bond Valence Sum ◽  
Bond Valence Model ◽  
Atomic Valence

The differences between Wang and Liebau's [Wang & Liebau (2007). Acta Cryst. B63, 216–228] stoichiometric valence (atomic valence) and structural valence (bond-valence sum) observed in Sn2+ and other lone-pair cation oxycomplexes arises from their use of the Brese & O'Keeffe bond-valence parameters which are based on the assumption that the bond-valence parameter b = 0.37 Å applies to all bond types. According to the theory of the bond-valence model, the bond-valence sum is necessarily equal to the ionic charge, implying that in the Wang and Liebau model the ionic charges are equal to the structural valence. If charges are chosen equal to the stoichiometric valence, the bond-valence parameters for Sn2+—O bonds are R 0 = 1.859 Å, b = 0.55 Å. While both models are theoretically valid, only the standard model relates bond valences to the concept of atomic valence. Wang and Liebau's suggestion that cation–lone-pair bonds make a significant contribution to the valence sums is confirmed, but such bonds cannot account for the full difference between the stoichiometric and structural valences because they are present in only a few compounds.

VALMAP2.0: contour maps using the bond-valence-sum method

1999 ◽  
Vol 32 (2) ◽  
pp. 341-344 ◽  
Author(s):  
Javier González-Platas ◽  
Cristina González-Silgo ◽  
Catalina Ruiz-Pérez
Keyword(s):  
Arbitrary Point ◽  
Bond Valence ◽  
Steric Effects ◽  
Contour Map ◽  
Structural Investigations ◽  
Disorder Phase Transition ◽  
Contour Maps ◽  
Bond Valence Sum ◽  
Bond Valence Model ◽  
Microsoft Windows

VALMAP2.0 is a Microsoft-Windows-based program designed to assist material scientists in accurate structural investigations. The aim ofVALMAPis to calculate the sum of bond valences that a particular atom would have if it were placed at any arbitrary point in the crystal. By movement of this atom through all possible points, its valence-sum contour map can be displayed. Parameters of the bond-valence model are available and may be modified. The program was tested in a number of cases and two examples of applications are reported: (i) finding probable atom sites in crystal structures; (ii) displacive and order–disorder phase transition mechanisms, analysing steric effects.

Universal `bond valenceversusbond length' correlation curve for manganese–oxygen bonds

2014 ◽  
Vol 70 (3) ◽  
pp. 608-611 ◽  
Author(s):  
Vasyl Sidey
Keyword(s):  
Bond Length ◽  
Oxidation State ◽  
Bond Valence ◽  
Acta Cryst ◽  
Correlation Curve ◽  
Bond Valence Model ◽  
Two Parameter

The oxidation-state independent `bond valence (s)versusbond length (r)' correlation curve for manganese–oxygen bonds has been closely approximated using the modified two-parameter Trömels=f(r) function [Trömel (1983).Acta Cryst.B39, 664–669],s= [(r0−l)/(r−l)]2, wherer0= 1.763 (2) Å andl= 1.148 (9) Å. Ther0andlrefinable parameters of the above function can be regarded as the alternative bond-valence parameters intended for use in the modern bond-valence model [Brown (2009).Chem. Rev.109, 6858–6919] in cases where the traditional bond-valence parameters (r0;n) and (r0;b) fail.

On the correlations between the polyhedron eccentricity parameters and the bond-valence sums for the cations with one lone electron pair

2008 ◽  
Vol 64 (4) ◽  
pp. 515-518 ◽  
Author(s):  
Vasyl Sidey
Keyword(s):  
Lone Electron Pair ◽  
Electron Pair ◽  
Bond Valence ◽  
Acta Cryst ◽  
Bond Valence Model

Applicability of the Wang–Liebau polyhedron eccentricity parameter in the bond-valence model [Wang & Liebau (2007). Acta Cryst. B63, 216–228] has been found to be doubtful: the correlations between the values of the polyhedron eccentricity parameters and the bond-valence sums calculated for the cations with one lone electron pair are probably an artifact of the poorly determined bond-valence parameters.

Crystallochemical analysis of the crystal structure of PbGa2S4: the bond valence model

2016 ◽  
Vol 39 (0) ◽  
pp. 7-11
Author(s):  
А. Я. Штейфан ◽  
В. І. Сідей ◽  
І. І. Небола ◽  
І. П. Студеняк
Keyword(s):  
Crystal Structure ◽  
Bond Valence ◽  
Bond Valence Model ◽  
Crystallochemical Analysis

scholarly journals Chemical-shift tensors of heavy nuclei in network solids: a DFT/ZORA investigation of 207Pb chemical-shift tensors using the bond-valence method

2015 ◽  
Vol 17 (38) ◽  
pp. 25014-25026 ◽  
Author(s):  
Fahri Alkan ◽  
C. Dybowski
Keyword(s):  
Chemical Shift ◽  
Quantum Chemistry ◽  
Principal Components ◽  
Bond Valence ◽  
Cluster Models ◽  
Magnetic Shielding ◽  
Heavy Nuclei ◽  
Chemical Shift Tensors ◽  
Accurate Computation ◽  
Bond Valence Model

Accurate computation of 207Pb magnetic shielding principal components is within the reach of quantum chemistry methods by employing relativistic ZORA/DFT and cluster models adapted from the bond valence model.

3DBVSMAPPER: a program for automatically generating bond-valence sum landscapes

2012 ◽  
Vol 45 (5) ◽  
pp. 1054-1056 ◽  
Author(s):  
Matthew Sale ◽  
Maxim Avdeev
Keyword(s):  
Computer Program ◽  
Three Dimensional ◽  
Bond Valence ◽  
Spatial Distributions ◽  
Energy Landscapes ◽  
Bond Valence Sum ◽  
Scripting Language ◽  
Materials Studio ◽  
User Intervention ◽  
Minimal User Intervention

A computer program,3DBVSMAPPER, was developed to generate bond-valence sum maps and bond-valence energy landscapes with minimal user intervention. The program is designed to calculate the spatial distributions of bond-valence values on three-dimensional grids, and to identify infinitely connected isosurfaces in these spatial distributions for a given bond-valence mismatch or energy threshold and extract their volume and surface area characteristics. It is implemented in the Perl scripting language embedded in AccelrysMaterials Studioand has the capacity to process automatically an unlimited number of materials using crystallographic information files as input.

A revisit of the bond valence model makes it universal

2020 ◽  
Vol 22 (25) ◽  
pp. 13839-13849 ◽  
Author(s):  
Elena Levi ◽  
Doron Aurbach ◽  
Carlo Gatti
Keyword(s):  
Quantum Chemistry ◽  
Chemical Bond ◽  
Bond Valence ◽  
Bond Orders ◽  
Chemistry Data ◽  
Bond Valence Model

The application of Pauling's principles to any type of chemical bond can be validated using recent quantum chemistry data (bond orders), thus making them universal.

Studies on bond and atomic valences. I. correlation between bond valence and bond angles in SbIII chalcogen compounds: the influence of lone-electron pairs

1996 ◽  
Vol 52 (1) ◽  
pp. 7-15 ◽  
Author(s):  
X. Wang ◽  
F. Liebau
Keyword(s):  
Statistical Analysis ◽  
Valence State ◽  
Lone Electron Pair ◽  
Electron Pair ◽  
Bond Valence ◽  
Continuous Change ◽  
Oxidation Number ◽  
Electron Pairs ◽  
Atomic Valence ◽  
Bond Valence Parameter

In the present bond-valence concept the bond-valence parameter ro is treated as constant for a given pair of atoms, and it is assumed that the bond valence sij is a function of the corresponding bond length Dij , and that the atomic valence is an integer equal to the formal oxidation number for Vi derived from stoichiometry. However, from a statistical analysis of 76 [SbIIIS n ] and 14 [SbIIISe n ] polyhedra in experimentally determined structures, it is shown that for SbIII—X bonds (X = S, Se), ro is correlated with {\bar \alpha} i , the average of the X—Sb—X angles between the three shortest Sb—X bonds. This is interpreted as a consequence of a progressive retraction of the 5s lone-electron pair from the SbIII nucleus, which can be considered as continuous change of the actual atomic valence act Vi of Sb from +3 towards +5. A procedure is derived to calculate an effective atomic valence eff Vi of SbIII from the geometry, {\bar \alpha} i and Dij , of the [SbIII Xn ] polyhedra, which approximates act Vi and is a better description of the actual valence state of SbIII than the formal valence for Vi . Calculated eff V SbIII are found to vary between +2.88 and +3.80 v.u. for [SbIIIS n ] and between +2.98 and +3.88 v.u. for [SbIIISe n ] polyhedra. It is suggested that a corresponding modification of the present bond-valence concept is also required for other cations with lone-electron pairs.

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