scholarly journals Non-empirical LCAO-MO-SCF-CI calculations on organic molecules with Graussian type functions

1967 ◽  
Vol 7 (2) ◽  
pp. 156-156 ◽  
Author(s):  
I. G. Csizmadia ◽  
M. C. Harrison ◽  
J. W. Moskowitz ◽  
B. T. Sutcliffe
Keyword(s):  
Organic Molecules ◽  
Ci Calculations ◽  
Lcao Mo

Non-empirical LCAO-MO-SCF-CI calculations on organic molecules with Gaussian type functions

1966 ◽  
Vol 6 (3) ◽  
pp. 217-239 ◽  
Author(s):  
I. G. Csizmadia ◽  
M. C. Harrison ◽  
B. T. Sutcliffe
Keyword(s):  
Organic Molecules ◽  
Gaussian Type ◽  
Ci Calculations ◽  
Lcao Mo

Non-empirical LCAO-MO-SCF-CI calculations on organic molecules with gaussian type functions

1967 ◽  
Vol 8 (4) ◽  
pp. 281-284 ◽  
Author(s):  
S. S. Seung ◽  
M. C. Harrison ◽  
I. G. Csizmadia
Keyword(s):  
Organic Molecules ◽  
Gaussian Type ◽  
Ci Calculations ◽  
Lcao Mo

Non-empirical LCAO-MO-SCF-CI calculations on organic molecules with Gaussian type functions

1966 ◽  
Vol 6 (3) ◽  
pp. 191-216 ◽  
Author(s):  
I. G. Csizmadia ◽  
M. C. Harrison ◽  
J. W. Moskowitz ◽  
B. T. Sutcliffe
Keyword(s):  
Organic Molecules ◽  
Gaussian Type ◽  
Ci Calculations ◽  
Lcao Mo

LCAO MO Investigations on Lignin Model Compounds VI. CNDO/CI Calculations of Electronic Spectra of Cinnamaldehyde Structures

1978 ◽  
Vol 33 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Milan Remko ◽  
Jan Polčin
Keyword(s):  
Electronic Absorption ◽  
Electronic Spectra ◽  
Electronic Absorption Spectra ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Transition Energies ◽  
Lignin Model ◽  
Ci Calculations ◽  
Good Agreement ◽  
Lcao Mo

The electronic absorption spectra of cinnamaldehyde, o-, m-, p-hydroxycinnamaldehyde and 3-methoxy-4-hydroxy cinnamaldehyde were theoretically and experimentally studied, by means of the semiempirical CNDO/CI method. The calculated and observed transition energies were in good agreement.

Localized molecular orbitals in CI calculations of organic molecules

1992 ◽  
Vol 83 (1-2) ◽  
pp. 123-139 ◽  
Author(s):  
Thomas Neuheuser ◽  
Malte Arnim ◽  
Sigrid D. Peyerimhoff
Keyword(s):  
Organic Molecules ◽  
Molecular Orbitals ◽  
Localized Molecular Orbitals ◽  
Ci Calculations

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Direct phase determination in electron crystallography: small organic molecules

1992 ◽  
Vol 50 (2) ◽  
pp. 1166-1167
Author(s):  
Douglas L. Dorset
Keyword(s):  
Organic Molecules ◽  
Data Sets ◽  
Temperature Structure ◽  
3D Analysis ◽  
Intensity Data ◽  
Electron Crystallography ◽  
Phase Determination ◽  
Measured Intensity ◽  
3D Data

The quantitative use of electron diffraction intensity data for the determination of crystal structures represents the pioneering achievement in the electron crystallography of organic molecules, an effort largely begun by B. K. Vainshtein and his co-workers. However, despite numerous representative structure analyses yielding results consistent with X-ray determination, this entire effort was viewed with considerable mistrust by many crystallographers. This was no doubt due to the rather high crystallographic R-factors reported for some structures and, more importantly, the failure to convince many skeptics that the measured intensity data were adequate for ab initio structure determinations.We have recently demonstrated the utility of these data sets for structure analyses by direct phase determination based on the probabilistic estimate of three- and four-phase structure invariant sums. Examples include the structure of diketopiperazine using Vainshtein's 3D data, a similar 3D analysis of the room temperature structure of thiourea, and a zonal determination of the urea structure, the latter also based on data collected by the Moscow group.

Sign in / Sign up

Export Citation Format

Share Document