A model of atoms in molecules based on potential acting on one electron in a molecule: I. Partition and atomic charges obtained from ab initio calculations

2018 ◽  
Vol 118 (15) ◽  
pp. e25610 ◽  
Author(s):  
Dong-Xia Zhao ◽  
Jian Zhao ◽  
Zun-Wei Zhu ◽  
Chao Zhang ◽  
Zhong-Zhi Yang
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Atoms In Molecules ◽  
Atomic Charges

The correspondence between Hückel theory and ab initio atomic charges in allyl ions

1988 ◽  
Vol 66 (11) ◽  
pp. 2961-2962 ◽  
Author(s):  
Tom S. Slee ◽  
Preston J. MacDougall
Keyword(s):  
Quantum Theory ◽  
Ab Initio ◽  
Atoms In Molecules ◽  
Atomic Charges ◽  
Allyl Cation ◽  
Hückel Theory ◽  
The Difference

Atomic charges for the allyl cation and anion are reported, as defined by the quantum theory of atoms in molecules. An interesting feature of these charges is that they differ considerably from expectations based on simple π orbital models. The reasons for the difference are investigated and it is shown that the charges are both compatible with and understandable in terms of simple orbital models.

Ab initio studies on 1,2-oxathietane, Z and E 3,4-dimethyl-1,2-oxathietane, and their products of formal [σ2s + σ2a] cycloreversion

1988 ◽  
Vol 66 (8) ◽  
pp. 1890-1894 ◽  
Author(s):  
Ali Naghipur ◽  
J. William Lown ◽  
Duli C. Jain ◽  
Anne-Marie Sapse
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Ground State ◽  
Atomic Charges ◽  
The Novel ◽  
Hartree Fock ◽  
Plausible Mechanism

Ab initio calculations at the level of 3-21G* SCF and MP3/3-21G* have been performed on the novel heterocycle 1,2-oxathietane and the formal [σ2s + σ2a] cycloreversion products. Hartree–Fock calculations have been performed for the E and Z 3,4-dimethyl-1,2-oxathietanes and their corresponding cycloreversion products. The calculations afford fully geometry optimized conformations, energies, net atomic charges, and HOMO values for the heterocycles. 1,2-Oxathietane is found to be close in energy to the sum of energies of either pair of its cycloreversion products. The most plausible mechanism of cycloreversion features the formation of ground state formaldehyde and thioformaldehyde via a biradical intermediate. This result is in accord with the lack of detection of chemiluminescence with the 1,2-oxathietanes, in contrast to the 1,2-dioxetanes.

scholarly journals Theoretical investigations of ZnO/CdO material – A DFT approach

2018 ◽  
Vol 6 (1) ◽  
pp. 79
Author(s):  
Rackesh Jawaher ◽  
Indirajith R ◽  
Krishnan S ◽  
Bharanidharan Bharani ◽  
Robert R ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Dihedral Angles ◽  
Atomic Charges ◽  
First Order ◽  
Nlo Property ◽  
Theoretical Investigations ◽  
Title Molecule ◽  
Homo Lumo

The theoretical investigations of ZnO/CdO material were carried out by using ab initio calculations. The bond parameters such as bond lengths, bond angles and dihedral angles were calculated at DFT/B3LYP/LANL2DZ level of theory. The NLO property of the title molecule was calculated using a first order hyperpolarizability calculation. NBO study reveals that the hyperconjucative interactions between the material. Homo-Lumo analysis the charge transfer occurs within the molecule. MEP surface predicts the reactive sites of the present molecule. In addition of Mulliken atomic charges and thermodynamic parameters were also plotted and calculated.

Cooperative and substitution effects in enhancing the strength of fluorine bonds by anion−π interactions

2015 ◽  
Vol 93 (11) ◽  
pp. 1169-1175 ◽  
Author(s):  
Mehdi D. Esrafili ◽  
Fariba Mohammadian-Sabet ◽  
Mohammad Mehdi Baneshi
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Atoms In Molecules ◽  
Substitution Effects ◽  
Cooperative Effects ◽  
Π Interactions ◽  
Binding Distance

In this work, the cooperative effects between anion−π and fluorine bond interactions are studied by ab initio calculations at the MP2/6-311++G** level. Cooperative effects are observed in complexes in which anion−π and fluorine bond interactions coexist. For each complex, the shortening of the binding distance in the fluorine bond is more prominent than that in the anion−π bond. Favorable cooperativity energies are found with values that range between –0.51 and –0.76 kcal/mol. The atoms in molecules and molecular electrostatic potential analyses are carried out for these complexes to understand the nature of anion−π and fluorine bond interactions and the origin of the cooperativity.

scholarly journals Theoretical Study of Mixed Hydrogen and Dihydrogen Bond Interactions in Clusters

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Abedien Zabardasti ◽  
Nahid Zare ◽  
Masoumeh Arabpour ◽  
Ali Kakanejadifard ◽  
Mohammad Solimannejad
Keyword(s):  
Hydrogen Bonds ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Theoretical Study ◽  
Cluster Formation ◽  
Blue Shift ◽  
Atoms In Molecules ◽  
Negative Cooperativity ◽  
Dihydrogen Bond ◽  
Dihydrogen Bonding

Ab initio calculations were used to analyze interactions of with 1–4 molecules of NH3at the MP2/6-311++G(d,p) and the B3LYP/6-311++G(d,p) computational levels. In addition to H3B–H⋯H–NH2dihydrogen bond, the H2N–H⋯NH3hydrogen bonds were also predicted in clusters. Negative cooperativity in clusters constructed from mixed H3B–H⋯H–NH2dihydrogen and H2N–H⋯NH3hydrogen bonds are more remarkable. The negative cooperativity increases with size and number of hydrogen bonds in cluster. The B–H stretching frequencies show blue shifts with respect to cluster formation. Greater blue shift in stretching frequencies was predicted for B–H bonds which did not contribute to dihydrogen bonding with NH3molecules. The structures were analyzed with the atoms in molecules (AIM) methodology.

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
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