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Author(s):  
Pascale Conjard-Réthoré
Keyword(s):  

1932 ◽  
Vol 54 (10) ◽  
pp. 4115-4116 ◽  
Author(s):  
Harold Hibbert ◽  
J. Stanley Allen


2021 ◽  
Author(s):  
JEJOON YEON ◽  
SANJIB C. CHOWDHURY ◽  
CHAITANYA M. DAKSHA ◽  
DONATO BELMONTE ◽  
ADRI VAN DUIN ◽  
...  

New ReaxFF parameters are developed for the description of Mg/Al/Si/O interaction for the Magnesium Aluminosilicate (MAS) glass structure. The training set contains energy curves from equation of state for various Mg/Al/Si/O crystals, valence angle and bond distance scan, and heat of formation for the Mg/Al/Si/O interactions. A semi-automated Genetic Algorithm assisted by Artificial Neural Network is applied for this parametrization. Validation efforts showed the current ReaxFF parameter set can describe the atomistic structure and property of tectosilicate MAS glass including S-glass. Estimated quasi-static modulus of S-glass structure matches well with experimental value. Analysis shows the key of high modulus of S-glass is numerous Mg-BO (Bridge Oxygen) interactions across the Mg-O-AlSi structure. In addition, atomistic origin of high ductility and progressive failure of S-glass is derived from the reconstruction of the atomic structure, forming Mg-BO-Si interactions that delays fracture formation.



Two new band systems have been observed in absorption following flash photolysis of AsH 3 and AsD 3 , and are assigned to 2 A 1 - 2 B 1 electronic transitions of AsH 2 and AsD 2 . The origins of both systems are at 19905 cm -1 . The bands have the complex rotational structure associated with an asymmetric rotor. Rotational analyses have been carried out for three bands of the AsH 2 spectrum, leading to the following molecular parameters: ground state, r" 0 = 1.518 Å valence angle = 90° 44'; excited state, r' 0 = 1.48 Å, valence angle = 123° 0'. The parameters associated with rotation about the a inertial axis increase rapidly with increase in v' 2 . The spectrum shows doublet splittings of up to 41 cm -1 , and the excited state furnishes the first example of a doublet state of an asymmetric top molecule which shows substantial departures from Hund’s case ( b ).



1942 ◽  
Vol 19 (1) ◽  
pp. 29
Author(s):  
W. H. Dore
Keyword(s):  


1999 ◽  
Vol 40 (37) ◽  
pp. 6717-6720
Author(s):  
Timothy A. Waugh ◽  
Joseph K. Agyin ◽  
John J. Nash ◽  
Harry Morrison
Keyword(s):  


1937 ◽  
Vol 5 (5) ◽  
pp. 371-371 ◽  
Author(s):  
Bryce L. Crawford ◽  
Paul C. Cross


1963 ◽  
Vol 18 (4) ◽  
pp. 496-504 ◽  
Author(s):  
H.-H. Schmidtke

In order to find an explanation for the WALSH rules on a more theoretical basis for molecules of type AB2 (non hydrides) a simple MO-LCAO calculation with SLATER-Functions of the L-shell was carried out. The results are presented as tables and graphs, which give the dependence of the one-electron energies on the valence angle. In accordance with WALSH’S rules the apex angle decreases with the number of electrons in the range of 16 to 20 valency electrons, molecules with not more than 16 valency electrons being linear.However according to the present calculation the reason for this is that with increasing number of electrons more orbitals are occupied which are lower in energy for the bent species, rather than WALSH’S explanation which lies in the increasing s-character of the πU non-bonding orbital.



1932 ◽  
Vol 54 (5) ◽  
pp. 1854-1862 ◽  
Author(s):  
C. P. Smyth ◽  
W. S. Walls




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