Slater Model Research Articles

Schizophrenia on paternal and maternal sides: an analysis of familial factors.

Slater's model of assessing distribution patterns of ancestral secondary cases in family trees was applied to pedigree data on schizophrenia. Eighteen schizophrenic probands with at least two ill second-degree relatives were available for study. The distribution of unilateral to bilateral pairs of affected relatives did not deviate significantly from that expected in polygenic inheritance. Contrasting pedigrees with family history of chronic schizophrenia with pedigrees loaded with 'soft spectrum' disorders, i.e., borderline schizophrenia, did not alter the consistency of the data with polygenic transmission.

Calculations of photoelectron spectra for tetrahedral oxyanions by the Hartree—Fock—Slater model

The electronic structures of typical oxyanions are studied using the discrete variational (DV)— Xα cluster method. The level structures calculated for the clusters correspond very well with the valence-state levels found in experimental XPS spectra. Theoretical intensities of the XPS peaks are evaluated, using the orbital populations obtained with the DV— Xα method together with atomic subshell photoionization cross-sections obtained in previous work with the same electron model. The results are in good agreement with experiment.

Configuration interaction (CI), coupled-cluster (CC) and many-body perturbation (MBPT) approaches in the unrestricted Hartree—Fock—Slater (UHFS) model

The unrestricted Hartree—Fock—Slater (UHFS) solution is regarded as a zero-order wavefunction for configuration interaction (CI), coupled-cluster (CC) and many-body perturbation (MBPT) approaches for large cluster compounds which are more or less collective in electronic nature. The present method is successfully applied to investigate weak δ–δ bonds and δ–δ* excitation energies in binuclear metal complexes such as Mo2Cl4−8.

Singlet unrestricted Hartree-Fock Slater (UHFS) model for unstable metalmetal bonds

The electronic properties of weak metalmetal bonds are investigated on the basis of the singlet unrestricted Hartree-Fock Slater (1UHFS) model. It is pointed out that the 1UHFS model is sufficiently useful in describing the electron-transfer processes in cluster compounds which are regarded as models of organic semiconducting complexes.

Electronic structure of UF 5

Non-relativistic and relativistic self-consistent Hartree—Fock—Slater and Dirac—Slater models have been used to calculate one-electron energy levels and ionization energies for UF 5. The calculations were performed in an assumed structure of C 4v symmetry with the uranium atom at the center of mass of the molecule. The spacing and level ordering are compared with earlier results obtained with the MS Xα method using the muffin-tin approximation. Connections with the multi-photon isotope separation scheme of UF 6 are discussed.

Calculations of ionization and excitation energies for SiH 3 X (X = F, Cl, Br and I) using the discrete variational Xα method

The electronic structure of silyl halide SiH 3 X molecules are investigated using the discrete variational Xα method based on the Hartree—Fock—Slater model. Theoretical ionization and excitation energies are in very good agreement with the experimental results of UPS and UV spectra. The effects of Si 3 d orbitals are found to be significant on the bondings and orbital energies.

Early- and late-onset bipolar affective disorder. A genetic study.

A group of 46 bipolar probands was divided equally into those with early (before age 30) and later onset. The only significant difference found was a higher morbidity risk for the relatives of the early-onset group. Slater's model for a polygenic transmission was found compatible with this group, but insufficient data prevented its application in the older-onset group. In all other respects, however, no significant differences were found. Age of onset of illness may be unhelpful in elucidating the genetic basis of affective disorder. Further progress will depend on the development of more sensitive mathematical models and the finding of specific genetic markers.

RELATIVISTIC SELF-CONSISTENT MOLECULAR ORBITAL CALCULATION FOR UF6

Abstract The relativistic self-consistent molecular orbital calculation was made for UF6 in the Dirac–Slater model. The one-electron energies, excitation energies and the effects of relativity are presented.

Approximate self-consistent-field Hartree—Fock—Slater calculations of the ionization energies for Ni(CO) 4

Simple approximate self-consistent-field calculations for Ni(CO) 4 are made in the Hartree—Fock—Slater model using numerical basis functions. Th

Calculations of molecular ionization energies using a self-consistent-charge Hartree–Fock–Slater method

A numerical-variational method for performing self-consistent molecular calculations in the Hartree–Fock–Slater (HFS) model is presented. The molecular wavefunctions are expanded in terms of basis sets constructed from numerical HFS solutions of selected one-center atomlike problems. The binding energies and wavefunctions for the molecules are generated using a discrete variational method for a given molecular potential. In the self-consistent-charge (SCC) approximation to the complete self-consistent-field (SCF) method the results of a Mulliken population analysis of the molecular eigenfunctions are used in each iteration to produce ’’atomic’’ occupation numbers. The simplest SCC potential is then obtained from overlapping spherical atomlike charge distributions. The molecular ionization energies are calculated using the transition-state procedure; results are given for CO, H2O, H2S, AlCl, InCl, and the Ni5O surface complex. The agreement between experimental and theoretical ionization energies for the free-molecule valence levels is generally within 1 eV. The simple SCC procedure gives a reasonably good approximation to the molecular potential, as shown by comparison with experiment, and with complete SCF calculations of Baerends et al. on CO, H2O, and H2S.

Relativistic energy levels and bonding in actinide hexaflourides

A fully relativistic self-consistent Dirac–Slater model has been used to calculate one-electron energy levels and charge distributions for UF6, NpF6, and PuF6. Analysis of ground state charge densities reveals 5fn populations similar to free atom states; we are able to distinguish between metal–ligand bonding levels and the optically active levels described by crystal field theory. Ultraviolet and optical excitations, as well as ionziation energies, are calculated using an approximate transition state procedure and found to be in reasonable agreement with experiment. The Coulomb correlation integral appearing in the determination of the nature of 5f orbitals in solids is discussed on the basis of the systematics observed in our transition state calculations.

Magnetooptik und elektronische Struktur der magnetisch ordnenden Europiumchalkogenide

The absorption coefficient and the interband Faraday rotation of EuS, EuSe and EuTe thin films have been measured as function of the photon energy (1–6 eV), the temperature (2.7–300 K) and the applied magnetic field (0–11.5 kOe). In addition a magnetic field modulation technique has been developed, with a resolution of 2 ⋅ 10−4 deg. This allows the measurement of the Faraday rotation in fields of only 100 Oe, which is important for metamagnetic samples with low critical fields. A Kramers-Kronig transformation of the Faraday rotation leads to the circular dichroism and from these two quantities and the optical constants the off-diagonal elements of the conductivity tensor have been computed. From a comparison of this experimental result with values obtained from a modified atomic model, we deduce the character of the involved transitions and the spin polarization of the occupied ground states (4f 7,p(anion)). In addition the ratio of exchange splitting to band width of the empty 5d final state can be evaluated. The fine structure of the first main peak is discussed in terms of Kasuya's coupling scheme between the 4f 6 multiplett and the excited 5d electron. In the antiferromagnetic EuTe the temperature dependence of the Faraday rotation does not follow the net magnetization of the sample for all photon energies, but some transitions show a “ferromagnetic” behavior. This is interpreted in Slater's model of the magnetic Brillouin zone.

Opacities of high temperature uranium plasmas

Cross sections for thermal radiation in a uranium plasma at solid state density and temperatures in the KeV range are presented. The bƒ-and ƒƒ-absorption of ions is described by Kramers-type formulae and scattering on electrons by the Thomson formula. The bƒ-contributions from different states of ionization and excitation are treated individually, using a Slater model for the mean ionization potential of each electron configuration. It is assumed that all terms of a configuration contribute to one common absorption edge, and that excited configurations give rise to hydrogen-like series. The resulting frequency-dependent cross sections are illustrated. For kT < 10 keV scattering is unimportant. Near the Planck maximum ( hν≅3kT), the main contributions to the overall absorption arise from the ionization of the ground configurations of the predominant ionization stages.

Comments on Electrostrictions in KH2PO4

The electrostrictions in KH 2 PO 4 are discussed. It is shown that both the spontaneous strain in the ferroelectric phase and the field-induced strain in the paraelectric phase can be interpreted in a unified fashion even in terms of the simplest Slater model by taking into account the coupling between the strain and the fraction of sideway H 2 PO 4 - radicals, r . The order parameter θ, previously introduced by other workers, may not be necessary for the explanation of the peculiar nateur of the electrostrictions in this material.

Lifetime distribution of energized molecules in unimolecular reactions

AbstractThe lifetime distribution of energized molecules is examined within the framework of classical description of the molecular dynamics and in the connection with model theories of unimolecular reactions. If the reacting molecule represents an ergodic system, the lifetime distribution function of the molecules represented immediately after activation by the points in the phase space region corresponding to the internal energy ϵ to ϵ + δϵ (RRKM model) may be introduced; in a non‐ergodic case, the distribution function may be defined in that part of this phase space region, the point of which satisfy a supplementary condition of decomposition (Slater's model). It is shown that allowing a rapid intramolecular redistribution of internal energy of the molecule in the originally harmonic model, we obtain lifetime densities approximating the exponential (random) density. Some general features of the lifetime distribution in an ensemble of molecules with a uniform phase space density after activation are deduced from the qualitative analysis of the phase space trajectories.

Product translational energy distributions from the harmonic model for unimolecular decomposition

Formulae for the distribution of relative translational energy of products from decomposition of collision complexes are derived from the Slater model of unimolecular rate theory. The development presented parallels the statistical transition state theory (RRKM) approach. Although a similar form of the energy distribution is found, the identical result is obtained in the classical limit only for the special case of a ‘loose’ complex configuration at the critical point.

Relativistic molecular calculations in the Dirac–Slater model

A new method is presented to calculate binding energies and eigenfunctions for molecules, using the Dirac–Slater Hamiltonian. A numerical basis set of four component wavefunctions is obtained from atom-like Dirac–Slater wavefunctions. A discrete variational method (DVM) has been applied to generate the binding energies and eigenfunctions for the molecule. Results are given for a series of molecules, including dihydrides H2X (X=O, S, Se, Te), diatomic indium halides InX (X=F, Cl, Br, I), and metal chlorides XCl (X=B, Al, Ga, In, Tl). Comparison is made with results from nonrelativistic calculations using the DVM with numerical Hartree–Fock–Slater-type wavefunctions and with other types of nonrelativistic calculations. In particular, relativistic level shifts and spin–orbit splitting have been analyzed. The theoretical ionization energies are compared with experimental results. Generally a very good agreement is obtained between the experimental and theoretical binding energies for the valence levels, calculated by a transition state procedure. Most of the calculations have been made with a minimal basis set consisting of the occupied atomic orbitals. For H2S calculations are also reported, using an extended basis set. The change in the binding energies for the valence levels is a few tenths of an eV compared with the results using a minimal basis.

Band model for the metal-semiconductor transition in NiS

A simplified form of Slater's model for treating exchange effects in an itinerant antiferromagnet is applied to hexagonal NiS. In this calculation, which involves the augmented-plane-wave (APW) method, the antiferromagnetic superlattice is introduced by adding a constant $+{V}_{s}$ and $\ensuremath{-}{V}_{s}$ to the potentials within the two nickel APW spheres in the nonmagnetic unit cell. It is found that this superlattice opens a narrow band gap at the NiS Fermi level when ${V}_{s}\ensuremath{\approx}0.04$ Ry. As a result, we conclude that the observed low-temperature nonmetallic behavior in NiS is due to the antiferromagnetic superlattice and does not involve a Mott-Hubbard transition.

Modified Slater Model in Kagome Lattice

Modified Slater Model in Kagome Lattice

Modified Slater Model in Kagomé Lattice

Modified Slater Model in Kagomé Lattice