Coexistence of three types of sodium motion in double molybdate Na9Sc(MoO4)6: 23Na and 45Sc NMR data and ab initio calculations

2020 ◽  
Vol 22 (1) ◽  
pp. 144-154
Author(s):  
Anton L. Buzlukov ◽  
Irina Yu. Arapova ◽  
Yana V. Baklanova ◽  
Nadezhda I. Medvedeva ◽  
Tatiana A. Denisova ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Double Molybdate ◽  
Ion Motion ◽  
Temperature Range ◽  
Nmr Data ◽  
Different Types

The coexistence of three different types of Na-ion motion has been revealed in the temperature range 300–750 K.

Crystal Structure of and ab initio Calculations on [(C6H5)(CH3)CH-NH]- P(O)(p-OC6H4CH3)2, Syntheses and Spectroscopic Characterization of N-Benzyl Phosphoramidic Acid (4-Methylphenyl)ester Derivatives

2005 ◽  
Vol 60 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Khodayar Gholivand ◽  
Zahra Shariatinia ◽  
Mehrdad Pourayoubi
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Spectroscopic Characterization ◽  
Crystalline Lattice ◽  
Independent Molecule ◽  
Nmr Data ◽  
Independent Molecules

Some new N-benzyl phosphoramidic acid (4-methylphenyl)ester derivatives were synthesized and characterized by 1H, 13C, 31P NMR and IR spectroscopy and elemental analysis. The structure of [(C6H5)(CH3)CH-NH]P(O)(p-OC6H4CH3)2 (2) was investigated. This compound exists in polymeric zigzag chains in the crystalline lattice produced by hydrogen bonding built from two alternating independent molecules. NMR data indicate two diastereotopic p-cresol groups as confirmed by Xray crystallography. Ab initio calculations were performed on the geometry of compound 2 at the UHF/6-311G** and B3LYP/6-311G** levels. The optimized structure of each independent molecule contains two different p-cresol groups, in agreement with the experimental results.

Vacancies and substitutional defects in multicomponent diboride Ti0.25Zr0.25Hf0.25Ta0.25B2: First-principle study

2021 ◽  
Author(s):  
Martin Matas ◽  
Alireza Farhadizadeh ◽  
Jiri Houska
Keyword(s):  
Experimental Data ◽  
Thermal Stability ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
High Thermal Stability ◽  
First Principle ◽  
Electrically Conductive ◽  
Different Types ◽  
Substitutional Defects ◽  
Formation Energies

Abstract We study the hard and electrically conductive multicomponent diboride Ti0.25Zr0.25Hf0.25Ta0.25B2 with high thermal stability by ab initio calculations. We focus on the effect of defects (either vacancies or C atoms, both relevant for numerous experiments including our own) on material characteristics. Different types, concentrations and distributions of defects were investigated, and the configurations leading to the lowest formation energies were identified. We show that the replacement of B by C is more unfavorable than the formation of B vacancies. We show that vacancies prefer to coalesce into a larger planar void, minimizing the number of broken B B bonds and the volume per atom, while carbon substitutions at boron sites do not prefer coalescence and tend to minimize the number of C-C bonds. We show the effect of vacancies on mechanical and electronic properties, and use the results to explain experimental data.

Millimetre-wave and infrared spectroscopy of Br13 CN: anharmonic force field of cyanogen bromide from spectroscopic data and ab initio calculations

1997 ◽  
Vol 90 (3) ◽  
pp. 495-497
Author(s):  
CLAUDIO ESPOSTI ◽  
FILIPPO TAMASSIA ◽  
CRISTINA PUZZARINI ◽  
RICCARDO TARRONI ◽  
ZDENEK ZELINGER
Keyword(s):  
Infrared Spectroscopy ◽  
Force Field ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Spectroscopic Data ◽  
Cyanogen Bromide ◽  
Millimetre Wave ◽  
Anharmonic Force

Ab Initio Calculations of Defects in CdMnSe Semimagnetic Semiconductors

2020 ◽  
Vol 55 (1) ◽  
pp. 108-113
Author(s):  
M. A. Mehrabova ◽  
H. S. Orujov ◽  
N. H. Hasanov ◽  
A. I. Kazimova ◽  
A. A. Abdullayeva
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Semimagnetic Semiconductors
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