Infrared Spectra of CF2═CHD and CF2═CD2: Scaled Quantum-Chemical Force Fields and an Equilibrium Structure for 1,1-Difluoroethylene

2010 ◽  
Vol 114 (34) ◽  
pp. 9309-9318 ◽  
Author(s):  
Donald C. McKean ◽  
Mark M. Law ◽  
Peter Groner ◽  
Andrew R. Conrad ◽  
Michael J. Tubergen ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Quantum Chemical ◽  
Force Fields ◽  
Equilibrium Structure ◽  
Chemical Force

Structure, spectra and internal rotation of bis(trimethylsilyl) acetylene: spectral analysis by scaling quantum-chemical force fields and two methods for calculating vibrational effects

2000 ◽  
Vol 523 (1-3) ◽  
pp. 1-22 ◽  
Author(s):  
V.A. Sipachev ◽  
L.S. Khaikin ◽  
O.E. Grikina ◽  
V.S. Nikitin ◽  
M. Trætteberg
Keyword(s):  
Spectral Analysis ◽  
Internal Rotation ◽  
Quantum Chemical ◽  
Force Fields ◽  
Chemical Force

The structure and spectra of 1-silylpropyne: scaled quantum-chemical force fields and vibrational effects

2001 ◽  
Vol 567-568 ◽  
pp. 85-99 ◽  
Author(s):  
L.S. Khaikin ◽  
O.E. Grikina ◽  
V.A. Sipachev ◽  
M. Traetteberg
Keyword(s):  
Quantum Chemical ◽  
Force Fields ◽  
Chemical Force

s-trans-1,3-Butadiene and Isotopomers:  Vibrational Spectra, Scaled Quantum-Chemical Force Fields, Fermi Resonances, and C−H Bond Properties

2006 ◽  
Vol 110 (26) ◽  
pp. 8044-8059 ◽  
Author(s):  
Donald C. McKean ◽  
Norman C. Craig ◽  
Yurii N. Panchenko
Keyword(s):  
Vibrational Spectra ◽  
Quantum Chemical ◽  
Force Fields ◽  
Bond Properties ◽  
Chemical Force ◽  
Fermi Resonances

Scaled Quantum Chemical Force Fields for 1,1-Difluorocyclopropane and the Influence of Vibrational Anharmonicity

2008 ◽  
Vol 112 (29) ◽  
pp. 6760-6771 ◽  
Author(s):  
Donald C. McKean ◽  
Norman C. Craig ◽  
Mark M. Law
Keyword(s):  
Quantum Chemical ◽  
Force Fields ◽  
Vibrational Anharmonicity ◽  
Chemical Force

Force Fields in Liquid and Solid Cu Metal: Relation Between Quantum Chemical and Density Functional Treatments

1998 ◽  
Vol 36 (4) ◽  
pp. 207-214 ◽  
Author(s):  
N. H. March ◽  
K. Ray
Keyword(s):  
Quantum Chemical ◽  
Density Functional ◽  
Force Fields

High Resolution Infrared Spectra of the ν2 and 2ν1 Bands of 14N16O2

1975 ◽  
Vol 53 (19) ◽  
pp. 1902-1926 ◽  
Author(s):  
Aldée Cabana ◽  
Michel Laurin ◽  
Walter J. Lafferty ◽  
Robert L. Sams
Keyword(s):  
High Resolution ◽  
Infrared Spectra ◽  
Ground State ◽  
Equilibrium Structure ◽  
Coriolis Interaction ◽  
Rotational Constants ◽  
Average Structures

The infrared spectra of two B type bands, ν2 and 2ν1, of 14N16O2 have been recorded under high resolution. Ground state combination differences from these bands have been combined with combination differences obtained in previous studies and eight pure rotational microwave transitions to yield improved ground state rotational constants. Upper state constants and band centers for the ν2 and 2ν1 bands are also reported. The 2ν1 band contains internal intensity anomalies believed to arise from a weak Coriolis interaction with the much stronger ν1 + ν3 band. Equilibrium rotational constants have been calculated. The equilibrium structure of the molecule is: rc = 1.1945 ± 0.0005 Å and Θc = 133.85 ± 0.10°. For the sake of comparison, effective, substitution, and average structures are also reported.

The Future

1992 ◽  
Author(s):  
John A. Tossell ◽  
David J. Vaughan
Keyword(s):  
Ab Initio ◽  
Quantum Chemical ◽  
Force Fields ◽  
Structural Characteristics ◽  
Future Research ◽  
Quantum Mechanical ◽  
Bond Lengths ◽  
Hartree Fock ◽  
Qualitative Level ◽  
Dynamics Simulations

In this final chapter, an attempt is made to provide an overview of the capabilities of quantum-mechanical methods at the present time, and to highlight the needs for future development and possible future applications of these methods, particularly in areas related to mineral structures, energetics, and spectroscopy. There is also a brief account of some new areas of application, specific directions for future research, and possible developments in the perception and use of quantum-mechanical approaches. The book ends with an epilog on the overall role of “theoretical geochemistry” in the earth and environmental sciences. The local structural characteristics of minerals such as Mg2SiO4, which contain only main-group elements, are reasonably well reproduced by ab initio Hartree-Fock-Roothaan (SCF) cluster calculations at the mediumbasis- set level. Calculations incorporating configuration interaction will inevitably follow and probably lead to somewhat better agreement with experiment. The most pressing needs in this area of study are for the development of systematic procedures for cluster selection and embedding, for a greater understanding of the results at a qualitative level, and for more widespread efficient application of the quantum-chemical results currently available. In the last area, substantial progress has already been made by Lasaga and Gibbs (1987), Sanders et al. (1984), Tsuneyuki et al. (1988), and others, who have used ab initio calculations to generate theoretical force fields which can then be used in molecular-dynamics simulations. If the characteristics of the resultant force fields can be understood at a first-principles level, then it may be possible to understand details of the simulated structures at the same level. Unfortunately, as regards a greater qualitative understanding of the quantum-mechanical calculations, little progress has been made. Rather old qualitative theories describe some aspects of bond-angle variation (Tossell, 1986), but no general model to interpret variations in bond lengths has been developed within either chemistry or geochemistry beyond the model of additive atomic (Slater) or ionic (Shannon and Prewitt) radii. Indeed, global theories of bond-length variations within an ab initio framework seem to be nonexistent. Nonetheless, quantum-chemical studies have shown the presence of intriguing systematics in bond lengths (Gibbs et al., 1987), which had been already noted empirically.

Fast and Accurate Quantum Chemical Modeling of Infrared Spectra of Condensed-Phase Systems

2020 ◽  
Vol 124 (30) ◽  
pp. 6664-6670 ◽  
Author(s):  
Sergey A. Katsyuba ◽  
Sebastian Spicher ◽  
Tatiana P. Gerasimova ◽  
Stefan Grimme
Keyword(s):  
Infrared Spectra ◽  
Condensed Phase ◽  
Quantum Chemical ◽  
Quantum Chemical Modeling ◽  
Chemical Modeling ◽  
Phase Systems
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