scholarly journals Visualization of Orbitals (11) ― Formation of Molecular Orbitals from the Interference of Atomic Orbitals

2021 ◽  
Vol 20 (2) ◽  
pp. A20-A25
Author(s):  
Sumio TOKITA
1980 ◽  
pp. 150-160
Author(s):  
Rudolf Zahradník ◽  
Rudolf Polák

2013 ◽  
Vol 798-799 ◽  
pp. 75-78
Author(s):  
Cai Xia Xu ◽  
Zhi Ping Huang ◽  
Qi Ping Fan ◽  
Wen Yu Zhang ◽  
Hong Yi Wu ◽  
...  

A molecular orbital is the wave function for the electron, and it extends over the entire molecule. When considering the possible reactions of a molecule, molecular orbitals are required to be known. This paper gives insight into the nature of molecular orbitals and nodal plane, also explain why certain atomic orbitals “missing” in molecular orbitals.


1960 ◽  
Vol 38 (11) ◽  
pp. 2117-2127 ◽  
Author(s):  
Richard F. W. Bader

The Hellmann–Feynman theorem has been employed to calculate the repulsion between two helium atoms and the molecular energies of H2 and H3. The method of molecular orbitals was used to determine the necessary expressions for the electron densities. The screening constants of the atomic orbitals comprising the molecular orbitals were treated as functions of the internuclear separation according to an empirical expression which duplicates very closely the "best" values for these parameters as determined by the variational method. The results of the calculations indicate that the present method is capable of yielding estimates of molecular energies which are comparable to those obtained by the more elaborate and time-consuming variational methods.


Photoelectron spectra of chloro-, fluoro- and chlorofluoroethylenes have been measured. Ionization potentials in the range 6 to 21 eV have been determined, and vibrational structure associated with many of the electronic transitions has been interpreted in terms of vibrations of the ion and correlated with those of the parent molecule. The various ionization potentials have been associated with specific orbitals such as the C=C π orbital, and molecular orbitals derived from the p atomic orbitals of halogens. Variations in these ionization potentials have been discussed in relation to inductive and conjugative effects of the halogen substituents. Some observed differences between the spectra of the chloro- and fluoroethylenes have been considered in relation to possible mechanisms of the changes in bond length consequent upon ionization.


2003 ◽  
Vol 18 (2) ◽  
pp. 31-35 ◽  
Author(s):  
Yury Teterin ◽  
Anton Teterin ◽  
Nikolay Yakovlev ◽  
Igor Utkin ◽  
Kirill Ivanov ◽  
...  

In this work an X-ray photoelectron spectroscopy study of nitrates Th(NO3)4.4H2O UO2(NO3)2-nH2O, Pu(NO3)4-nH2O, and Am(NO3)2.nH2O was done in the binding energy range from 0 to 1000 eV in order to draw a correlation of the fine spectral structure parameters with the actinide ions oxidation states close environment structure, and chemical bond nature. The linearity of the dependence of the An5fn line intensity on the number n5f of the An5f electrons was proven to remain up to the Am3+ ion with the electron configu5fra-tion{Rn 5f6. The spectral structure in the binding energy range from 0 to ~ 15 eV was associated with the formation of the outer valence molecular orbitals due to the interaction of the An6d-, 7s, 5f - O2p electrons, and the fine spectral structure in the binding energy range from ~ 15 to ~50 eV - with the formation of the inner valence molecular orbitals due to the interaction of the An6p - O2s electrons from the filled neighboring atomic orbitals of actinide and oxygen in the studied compounds. The fine structure of the core level electron spectra in the binding energy range from ~50 to 1000 eV was shown to correlate with the actinide ion oxidation state.


Energies of excitation of different electronic states of the oxygen molecule are calculated by the method of antisymmetrized molecular orbitals (ASMO). These are compared with the observed spectrum. It is found that the ASMO theory is most disappointing. The reasons for the failure of the method are analyzed. As a result of this critical analysis, a modified method is proposed which is found to be very successful. The basis of this modification is that the approximation of using atomic orbitals should be made only in evaluating the interaction energy of the constituent atoms of a molecule, and not to assess their isolated term values. As a corollary, the location of two new states of the oxygen molecule is predicted.


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