Relation between electronic structure and coordination number for boron clusters

1985 ◽  
Vol 20 (5) ◽  
pp. 565-567
Author(s):  
S. A. Prosandeev ◽  
Yu. B. Paderno ◽  
V. P. Sachenko
Keyword(s):  
Electronic Structure ◽  
Coordination Number ◽  
Boron Clusters

scholarly journals Effect of the Free Volume on the Electronic Structure of Cu70Zr30 Metallic Glasses

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4911
Author(s):  
Simon Evertz ◽  
Jochen M. Schneider
Keyword(s):  
Electronic Structure ◽  
Bond Strength ◽  
Coordination Number ◽  
Free Volume ◽  
Metallic Glasses ◽  
Volume Content ◽  
Short Distance ◽  
Volume Fraction ◽  
Plastic Behavior ◽  
Local Bonding

While it is accepted that the plastic behavior of metallic glasses is affected by their free volume content, the effect on chemical bonding has not been investigated systematically. According to electronic structure analysis, the overall bond strength is not significantly affected by the free volume content. However, with an increasing free volume content, the average coordination number decreases. Furthermore, the volume fraction of regions containing atoms with a lower coordination number increases. As the local bonding character changes from bonding to anti-bonding with a decreasing coordination number, bonding is weakened in the volume fraction of a lower coordination number. During deformation, the number of strong, short-distance bonds decreases more for free volume-containing samples than for samples without free volume, resulting in additional bond weakening. Therefore, we show that the introduction of free volume causes the formation of volume fractions of a lower coordination number, resulting in weaker bonding, and propose that this is the electronic structure origin of the enhanced plastic behavior reported for glasses containing free volume.

Electronic Structure and Properties of Silicon-Doped Boron Clusters BnSi with n = 15–24 and Their Anions

2020 ◽  
Vol 124 (12) ◽  
pp. 6770-6783 ◽  
Author(s):  
Dang Thi Tuyet Mai ◽  
Long Van Duong ◽  
My Phuong Pham-Ho ◽  
Minh Tho Nguyen
Keyword(s):  
Electronic Structure ◽  
Structure And Properties ◽  
Boron Clusters ◽  
Silicon Doped

scholarly journals New theoretical insight into high coordination number complexes in actinides-centered borane

2020 ◽  
Author(s):  
Shuxian Hu ◽  
Peng Zhang ◽  
wenli zou ◽  
ping zhang
Keyword(s):  
Coordination Number ◽  
Relativistic Quantum ◽  
Structural Motif ◽  
Strong Interactions ◽  
Valuable Insight ◽  
Cage Structure ◽  
Boron Clusters ◽  
Geometric Difference ◽  
High Coordination Number ◽  
High Coordination

<p>The coordination number of a given element behaving to understand its chemistry shows a great interest, which greatly promotes the extension and development of new materials, but remains challenging. Herein we report a new record high coordination number (CN) for actinide established in the cage-like An(BH)<sub>24</sub> (An = Th to Cm) via using relativistic quantum chemistry methods. Analysis of U(BH)<sub>n</sub> (n = 1 to 24) confirms these series of systems being as geometric minima, with the BH as a ligand located in the first shell around the uranium. Contrast, global searches reveal the low CN half-cage structure for UB<sub>24</sub>, which is extended to the series of AnB<sub>24</sub> and prevails over the competing structural isomers such as cage. The intrinsic geometric difference for AnB<sub>24 </sub>and An(BH)<sub>24</sub> mainly arise from the B sp<sup>3</sup> hybridization in borane inducing strong interactions between An 5f6d7s hybrid orbitals and B 2p<sub>z</sub> orbitals in An(BH)<sub>24</sub> comparing to that of AnB<sub>24</sub>. The fundamental trend presents a valuable insight for future experimental endeavor searching for isolable complexes with high-coordination actinide and provides a new structural motif of boron clusters and nanostructures.<br></p>

Connections Between 11B NMR Chemical Shifts and Electronic Structure in Metallaboranes. A Précis

1999 ◽  
Vol 64 (5) ◽  
pp. 767-782 ◽  
Author(s):  
Thomas P. Fehlner
Keyword(s):  
Electronic Structure ◽  
Chemical Shift ◽  
Transition Metal ◽  
Coordination Number ◽  
Chemical Shifts ◽  
Metal Cluster ◽  
Short Review ◽  
Electronic Charge ◽  
Chemical Shift Change ◽  
11B Nmr

An analysis of selected sets of metallaboranes in terms of a molecular orbital (MO) model of 11B chemical shift change is used to demonstrate the origin of transition metal effects on boron shifts for: (i) M-B edge protonation; (ii) replacement of direct B-B by M-B interactions; (iii) encapsulation of B in a metal cluster; (iv) change in metal identity; and (v) change in vertex coordination number. Metal effects on both filled and unfilled MO's are important but changes in the latter appear to dominate. Consequently, models based solely on filled orbital properties, e.g., electronic charge, are inadequate. A short review with 56 references.

scholarly journals Robustness of surface activity electronic structure-based descriptors of transition metals

2018 ◽  
Vol 20 (31) ◽  
pp. 20548-20554 ◽  
Author(s):  
Lorena Vega ◽  
Biel Martínez ◽  
Francesc Viñes ◽  
Francesc Illas
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Transition Metals ◽  
Coordination Number ◽  
Surface Activity ◽  
Metal Surfaces ◽  
Surface States ◽  
Density Functionals ◽  
Direct Relation ◽  
Transition Metal Surfaces

The d-band centre comes back from the dead being the most consistent of the main electronic descriptors, due to its excellent transferability between five density functionals. The robustness previously observed for bulk is here evaluated for transition metal surfaces and if large surface states are not involved, a direct relation with the coordination number is disclosed.

Theoretical probing of twenty-coordinate actinide-centered boron molecular drums

2021 ◽  
Author(s):  
Juan Wang ◽  
Nai-Xin Zhang ◽  
Congzhi Wang ◽  
Qunyan Wu ◽  
Jianhui Lan ◽  
...  
Keyword(s):  
Coordination Number ◽  
Boron Clusters ◽  
High Coordination Number ◽  
Metal Doped ◽  
High Coordination

The exploration of metal-doped boron clusters has a great significance to design high coordination number (CN) compounds. Actinide-dopted boron clusters are probably candidates for achieving high CNs. In this work,...

Reassessment of the Electronic Structure of Cr(VI) Sites Supported on Amorphous Silica and Implications for Cr Coordination Number

2018 ◽  
Vol 122 (8) ◽  
pp. 4349-4358 ◽  
Author(s):  
Nathan M. Peek ◽  
David B. Jeffcoat ◽  
Cristina Moisii ◽  
Lambertus van de Burgt ◽  
Salvatore Profeta ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Coordination Number ◽  
Amorphous Silica

PHOTOEMISSION STUDIES OF Pd AND Pt IMPURITIES ON AND IN SILVER

1996 ◽  
Vol 10 (24) ◽  
pp. 1161-1174 ◽  
Author(s):  
W.-D. SCHNEIDER ◽  
F. PATTHEY ◽  
H.-V. ROY ◽  
M.-H. SCHAFFNER ◽  
B. DELLEY
Keyword(s):  
Electronic Structure ◽  
Coordination Number ◽  
Impurity Atom ◽  
Photoelectron Spectroscopy ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Many Body ◽  
Dilute Alloys ◽  
Impurity Model ◽  
Single Impurity ◽  
Different Temperatures

The electronic structure of Pd and Pt atoms adsorbed on the (100), (110), and (111) surfaces of silver and of the related dilute alloys has been studied at different temperatures using ultraviolet photoelectron spectroscopy (UPS). The observed differences in lineshape of the virtual bound palladium 4d (platinum 5d) state on isolated atoms supported on the differently oriented surfaces in comparison with an impurity atom embedded in the first layer and in the bulk are well accounted for by a many-body calculation performed within the Anderson single impurity model. This analysis clearly indicates a stronger sd-hybridization in the bulk than at the surface, consistent with the change in coordination number.

Electronic Structure and Chemical Bonding in the Double Ring Tubular Boron Clusters

2014 ◽  
Vol 118 (41) ◽  
pp. 24181-24187 ◽  
Author(s):  
Hung Tan Pham ◽  
Long Van Duong ◽  
Minh Tho Nguyen
Keyword(s):  
Electronic Structure ◽  
Chemical Bonding ◽  
Boron Clusters ◽  
Double Ring
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