A decomposition of the number of effectively unpaired electrons and its physical meaning

2009 ◽  
Vol 476 (1-3) ◽  
pp. 101-103 ◽  
Author(s):  
Luis Lain ◽  
Alicia Torre ◽  
Diego R. Alcoba ◽  
Roberto C. Bochicchio
2009 ◽  
Vol 179 (7) ◽  
pp. 801 ◽  
Author(s):  
Aleksandr V. Kukushkin
Keyword(s):  

2017 ◽  
Author(s):  
Robson de Farias

<p>In the present work, a computational study is performed in order to clarify the possible magnetic nature of gold. For such purpose, gas phase Au<sub>2</sub> (zero charge) is modelled, in order to calculate its gas phase formation enthalpy. The calculated values were compared with the experimental value obtained by means of Knudsen effusion mass spectrometric studies [5]. Based on the obtained formation enthalpy values for Au<sub>2</sub>, the compound with two unpaired electrons is the most probable one. The calculated ionization energy of modelled Au<sub>2</sub> with two unpaired electrons is 8.94 eV and with zero unpaired electrons, 11.42 eV. The difference (11.42-8.94 = 2.48 eV = 239.29 kJmol<sup>-1</sup>), is in very good agreement with the experimental value of 226.2 ± 0.5 kJmol<sup>-1</sup> to the Au-Au bond<sup>7</sup>. So, as expected, in the specie with none unpaired electrons, the two 6s<sup>1</sup> (one of each gold atom) are paired, forming a chemical bond with bond order 1. On the other hand, in Au<sub>2</sub> with two unpaired electrons, the s-d hybridization prevails, because the relativistic contributions. A molecular orbital energy diagram for gas phase Au<sub>2</sub> is proposed, explaining its paramagnetism (and, by extension, the paramagnetism of gold clusters and nanoparticles).</p>


2008 ◽  
Vol 607 ◽  
pp. 64-66
Author(s):  
Nicolas Laforest ◽  
Jérémie De Baerdemaeker ◽  
Corine Bas ◽  
Charles Dauwe

Positron annihilation lifetime measurements on polymethylmethacrylate (PMMA) at low temperature were performed. Different discrete fitting procedures have been used to analyze the experimental data. It shows that the extracted parameters depend strongly on the fitting procedure. The physical meaning of the results is discussed. The blob model seems to give the best annihilation parameters.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Maciej Kolanowski ◽  
Jerzy Lewandowski

Abstract We generalize a notion of ‘conserved’ charges given by Wald and Zoupas to the asymptotically de Sitter spacetimes. Surprisingly, our construction is less ambiguous than the one encountered in the asymptotically flat context. An expansion around exact solutions possessing Killing vectors provides their physical meaning. In particular, we discuss a question of how to define energy and angular momenta of gravitational waves propagating on Kottler and Carter backgrounds. We show that obtained expressions have a correct limit as Λ → 0. We also comment on the relation between this approach and the one based on the canonical phase space of initial data at ℐ+.


2020 ◽  
Vol 130 (3) ◽  
pp. 30005
Author(s):  
E. Gravanis ◽  
E. Akylas ◽  
G. Livadiotis
Keyword(s):  

Carbon ◽  
1996 ◽  
Vol 34 (6) ◽  
pp. 828-831 ◽  
Author(s):  
F. Ehrburger-Dolle

Eos ◽  
2004 ◽  
Vol 85 (19) ◽  
pp. 188 ◽  
Author(s):  
Y. Kamide ◽  
G. Rostoker
Keyword(s):  

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