The gentle collective internal oscillation in the ground state of four-valence-electron atoms

1993 ◽  
Vol 26 (24) ◽  
pp. 4671-4682 ◽  
Author(s):  
Bao Cheng-Guang
Keyword(s):  
Ground State ◽  
Valence Electron ◽  
Internal Oscillation

Radikalionen, 62 [ 1—3]Bis(dimethyIamino)dibenzoheptafulven-Radikalkation /Radical Ions, 62 [1—3]Bis(dimethylamino)dibenzoheptafulvene Radical Cation

1984 ◽  
Vol 39 (6) ◽  
pp. 771-777 ◽  
Author(s):  
Hans Bock ◽  
Bernhard Roth ◽  
Jörg Daub
Keyword(s):  
Ionization Potential ◽  
Radical Cation ◽  
Ground State ◽  
Title Compound ◽  
Valence Electron ◽  
Esr Spectra ◽  
Vertical Ionization Potential ◽  
Radical Ions ◽  
Mndo Calculations ◽  
Multiplet Signal

AbstractThe neutral title compound, 8,8-bis(dimethylamino)dibenzo-[a,d]-heptafulvene, exhibits a first vertical ionization potential of only 6.98 eV and, therefore, can also be oxidized by AlCl3 in H2CCl2 solution. The radical cation generated shows a complex multiplet signal pattern, which is assigned based on additional ENDOR measurements. The photoelectron (PE) and ESR spectra of the 112 valence electron molecule are interpreted by “pararneter-optimized” HMO and by geometry-optimized MNDO calculations, which both suggest a non-planar π-type ground state with most of the charge and the spin distributed over the dibenzoheptatriene part of the radical cation.

The electronic spectrum of the CS+ molecular ion: rotational analysis and perturbation effects in the A2Πi–X2Σ+ transition

1978 ◽  
Vol 56 (5) ◽  
pp. 587-600 ◽  
Author(s):  
D. Gauyacq ◽  
M. Horani
Keyword(s):  
Carbon Disulfide ◽  
Ground State ◽  
Valence Electron ◽  
Band System ◽  
Local Perturbation ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Molecular Ion ◽  
Vibrational Levels ◽  
The Difference

A new emission spectrum in the red region (6000–8000 Å) has been recorded from a low pressure hot cathode discharge through carbon disulfide. This band system has been assigned to the A2Πi–X2Σ+ transition of the CS+ molecular ion on the basis of the rotational analysis and comparison with other nine valence-electron molecules. Molecular constants have been obtained by direct least squares fits of the line frequencies to the difference of the eigenvalues of standard 2Π and 2Σ+ matrices.A local perturbation in the A2Πi (ν = 5) state has been studied quantitatively. The position of the perturbing vibrational level in the X2Σ+ state has been determined within a few centimetre−1. This study gave a consistent set of molecular constants for the ground state of CS+ and allowed a partial deperturbation treatment of the observed vibrational levels of the excited A2Πi state.Numerous bands are also observed in the 4000 Å region. A discussion is given concerning the possible assignment of bands at 4059 and 4110 Å to the CS+B2Σ+–A2Πi (0,0) transition.

Variational Quantum Monte Carlo Calculation of Materials Properties

1988 ◽  
Vol 141 ◽  
Author(s):  
Steven G. Louie
Keyword(s):  
Monte Carlo ◽  
Ground State ◽  
Quantum Monte Carlo ◽  
Valence Electron ◽  
Monte Carlo Calculation ◽  
Core Region ◽  
Materials Properties ◽  
The Core ◽  
Large Fluctuations ◽  
Electron Wavefunction

AbstractA new method of calculating the total energy and other ground-state properties of solids which employs nonlocal pseudopotentials in conjunction with the variational quantum Monte Carlo approach is presented. Valence electron correlations are treated using the exact interaction with a correlated many-electron wavefunction of the Jastrow-Slater form. The use of pseudopotentials for the electron-ion interaction removes from the problem the large fluctuations of electron energies in the core region which occur in quantum Monte Carlo all-electron schemes. We discuss calculation of the cohesive energy and structural properties of diamond and graphite and the ionization energy and electron affinity of atoms using the present approach. The results are in excellent agreement with experiment.

Electronegativity and Average Local Ionization Energy

2005 ◽  
Vol 70 (5) ◽  
pp. 550-558 ◽  
Author(s):  
Peter Politzer ◽  
Jane S. Murray ◽  
M. Edward Grice
Keyword(s):  
Ground State ◽  
Ionization Energy ◽  
Valence Electron ◽  
Electronic Density ◽  
Average Valence ◽  
Average Local Ionization Energy ◽  
Valence Electrons ◽  
Ground State Atom ◽  
Average Local Ionization Energies ◽  
Calculated Average

A variation of an earlier formulation of electronegativity by Allen, as the average valence electron ionization energy of a ground-state atom, is proposed. It is shown that the calculated average local ionization energies on the 0.001 a.u. electronic density contours of atoms correlate very well with Allen's values. Our procedure makes it unnecessary to enumerate valence electrons, which can be a problem due to interpenetration of shells.

Investigations of Substituent Effects by Nuclear Magnetic Resonance Spectroscopy and All-valence Electron Molecular Orbital Calculations. IV. 4-Substituted Phenylacetylenes

1975 ◽  
Vol 53 (3) ◽  
pp. 373-382 ◽  
Author(s):  
Daniel A. Dawson ◽  
William F. Reynolds
Keyword(s):  
Molecular Orbital ◽  
Ground State ◽  
Valence Electron ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Resonance Spectroscopy ◽  
Molecular Orbital Calculations ◽  
Polarization Effects ◽  
Charge Densities ◽  
State Charge

13C and 1H spectra have been determined for 18 4-substituted phenylacetylenes and carbon charge densities have been estimated by CNDO/2 molecular orbital calculations. Correlations of these parameters with σ1, and σR0 indicate that the important mechanisms of transmission of substituent effects are field, resonance, and π polarization effects, as previously noted for 4-substituted styrenes. Evidence is presented that demonstrates that both 1H and 13C chemical shifts for these compounds reflect ground state charge densities. CNDO/2 calculations on a variety of aromatic derivatives suggest that the σ1, dependence of 19F chemical shifts in these derivatives may primarily be due to π polarization.

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