CHARGE DENSITIES AT THE NUCLEUS

1966 ◽  
Vol 44 (12) ◽  
pp. 3131-3135 ◽  
Author(s):  
Gulzari Malli ◽  
Serafin Fraga
Keyword(s):  
Negative Ions ◽  
Basis Sets ◽  
Neutral Atoms ◽  
Charge Densities ◽  
Hartree Fock ◽  
Positive Ions ◽  
Electronic Densities ◽  
Selection Of

The electronic densities and their derivatives at the nucleus for neutral atoms, positive ions, and negative ions (for Z = 2–36) have been evaluated, using analytical Hartree–Fock functions. These values confirm the discussion given in regard to the selection of the basis sets to be used in the expansion of the orbitals.

Slater–Condon parameters for the transition elements, evaluated from analytical Hartree–Fock functions

1968 ◽  
Vol 46 (19) ◽  
pp. 2228-2229
Author(s):  
Carolyn Fisk ◽  
Serafin Fraga
Keyword(s):  
Negative Ions ◽  
Neutral Atoms ◽  
Transition Elements ◽  
Hartree Fock ◽  
Positive Ions

The Slater–Condon integrals for the positive ions, neutral atoms, and negative ions from Sc to Zn have been evaluated from analytical Hartree–Fock functions.

Slater–Condon parameters for the atoms gallium to krypton, evaluated from analytical Hartree–Fock functions

1969 ◽  
Vol 47 (6) ◽  
pp. 637-637
Author(s):  
Carolyn Fisk ◽  
Serafin Fraga
Keyword(s):  
Negative Ions ◽  
Neutral Atoms ◽  
Hartree Fock ◽  
Positive Ions

The Slater–Condon integrals for the positive ions, neutral atoms, and negative ions from Ga to Kr have been evaluated from analytical Hartree–Fock functions.

Slater–Condon parameters evaluated from analytical Hartree–Fock functions

1968 ◽  
Vol 46 (9) ◽  
pp. 1140-1141 ◽  
Author(s):  
Carolyn Fisk ◽  
Serafin Fraga
Keyword(s):  
Negative Ions ◽  
Neutral Atoms ◽  
Hartree Fock ◽  
Positive Ions

The Slater–Condon integrals for the positive ions, neutral atoms, and negative ions from He to Ar have been evaluated from analytical Hartree–Fock functions.

scholarly journals Dissociation, recombination and attachment processes in the upper atmosphere II. The rate of recombination

1939 ◽  
Vol 170 (942) ◽  
pp. 322-340 ◽  
Keyword(s):  
Negative Ions ◽  
Neutral Molecule ◽  
Upper Atmosphere ◽  
The Other ◽  
Negative Ion ◽  
Neutral Atoms ◽  
Attachment Rate ◽  
Additional Advantage ◽  
Positive Ions ◽  
Positive Ion

The ionized regions of the upper atmosphere include, not only neutral atoms and molecules, electrons and positive ions, but also negative ions. Of these, electrons are alone effective in producing reflexion of wireless waves; so that an electron attached to a neutral molecule to form a negative ion is as effectively removed from active participation in these phenomena as one recombined with a positive ion to form a neutral molecule. The decay of electron density at night has been attributed by some authors to recombination with positive.ions and by others to attachment by neutral molecules. The first process is in agreement with the observed law of decay and has the additional advantage of making it easily possible to understand the formation of layers of concentrated ionization; on the other hand, the chance of attachment to a molecule per impact would have to be extremely small for the attachment rate to be negligible, since the number of collisions per second with neutral atoms is very much greater than with positive ions.

Effect of Basis Sets on the Selection of the Level of Theory Toward the Development of Quantum-Based Force Field Equation for Ionic Liquids

2005 ◽  
Vol 5 (2) ◽  
pp. 156 ◽  
Author(s):  
A. N. Soriano ◽  
B. T. Doma, Jr.
Keyword(s):  
Ionic Liquids ◽  
Field Equation ◽  
Volatile Organic Compounds ◽  
Force Field ◽  
Organic Compounds ◽  
Basis Set ◽  
Basis Sets ◽  
Hartree Fock ◽  
Volatile Organic ◽  
Selection Of

The chemical industry is under considerable pressure to replace many of the volatile organic compounds. Volatile organic compounds are a major contributor to air pollution, but out of necessity, they are still frequently used in many chemical and industrial processes. A new class of solvents, referred to as ionic liquids, may offer at least a partial solution to the pollution problem caused by volatile organic compounds. Ionic liquids are generally considered "green" solvents because of their environment-friendly properties. However, the main problem that hinders the chemical industry from using ionic liquids is that, compared to conventional organic solvents, relatively little is known about their thermodynamic and transport properties. Since there are large possible combinations of ionic liquids, it would be very expensive if the study were conducted in the laboratory. The more appropriate approach in studying the properties of ionic liquids is to engage in a computational method, which uses a computer software that evaluates ionic liquids' thermophysical quantities via quantum mechanical and molecular mechanical simulations. In this study, a computer simulation, with the aid of SPARTAN '02 software, is used to study the effect of basis sets on the selection of the appropriate level of theory, which would be employed later in developing a quantum-based force field equation for predicting the properties of ionic liquids. Using the Hartree-Fock self-consistent filled (HF-SCF) molecular orbital model with different basis sets, a single point energy calculations were carried out for the chosen ionic liquid. With the exception of the minimal basis set, the SCF total energies for the other basis sets agree with each other in terms of magnitude. The SCF total energy is not affected as the basis set varies from minimal to split valence and as it polarizes. The most appropriate basis set was found to be 6-31G*. Keywords: Basis sets, Hartree-Fock, ionic liquids, force field equation, level of theory, and SPARTAN '02.

Electronic Structure of the Transition Elements

1973 ◽  
Vol 51 (6) ◽  
pp. 644-647
Author(s):  
K. M. S. Saxena ◽  
S. Fraga
Keyword(s):  
Electronic Structure ◽  
Excited States ◽  
Ground State ◽  
Ground States ◽  
Negative Ions ◽  
State Function ◽  
Transition Elements ◽  
Hartree Fock ◽  
Positive Ions ◽  
Single Set

Numerical Hartree–Fock functions have been determined for the ground states and first excited states of the configurations 3dN4s0 and 3dN4s2 for the negative ions, neutral atoms, and first four positive ions of all the transition elements. The validity of the approximation, embodied in the use of a single set of parameters determined from the ground state function of a configuration for the prediction of the spectroscopic levels arising from it, has been examined in detail in the case of Fe I, 3d64s2, where independent calculations have been carried out for all the excited states.

Xα local spin density calculations of the 1:1 hydrogen-bonded complexes formed by water, ammonia, and hydrogen fluoride

1990 ◽  
Vol 68 (7) ◽  
pp. 1233-1237 ◽  
Author(s):  
E. C. Vauthier ◽  
V. Barone ◽  
C. Minichino ◽  
S. Fliszàr
Keyword(s):  
Spin Density ◽  
Basis Sets ◽  
Local Spin Density Approximation ◽  
Hartree Fock ◽  
Dissociation Energies ◽  
Local Spin ◽  
Extended Basis ◽  
Selection Of ◽  
Bonded Complexes ◽  
Hydrogen Bonded

The dissociation energies of the 1:1 hydrogen-bonded complexes formed by NH3, H2O, and HF were computed in the LCGTO-Xα local spin density approximation using extended basis sets. Attention was given to the appropriate selection of α. The order of stability of the various complexes reflects well their acid–base properties, in general agreement with experimental data and refined post Hartree–Fock computations. Keywords: hydrogen bonds, Xα method, local spin density method.

Sign in / Sign up

Export Citation Format

Share Document