Hartree–Fock formalism for the calculation of total energies and charge densities of thin films

1979 ◽  
Vol 16 (5) ◽  
pp. 1318-1322 ◽  
Author(s):  
Frank E. Harris ◽  
Hendrik J. Monkhorst ◽  
William A. Schwalm
Keyword(s):  
Thin Films ◽  
Charge Densities ◽  
Hartree Fock ◽  
Total Energies

scholarly journals EXPANSION FORMULAE FOR ONE- AND TWO-CENTER CHARGE DENSITIES OVER COMPLETE ORTHONORMAL SETS OF EXPONENTIAL TYPE ORBITALS AND THEIR USE IN EVALUATION OF MULTICENTER–MULTIELECTRON INTEGRALS

2009 ◽  
Vol 08 (04) ◽  
pp. 597-602 ◽  
Author(s):  
I. I. GUSEINOV
Keyword(s):  
Exponential Type ◽  
Overlap Integrals ◽  
Charge Densities ◽  
Hartree Fock ◽  
Expansion Formulae ◽  
Multicenter Multielectron Integrals ◽  
Explicitly Correlated ◽  
Explicitly Correlated Methods ◽  
Exponential Type Orbitals ◽  
The One

The series expansion formulae are established for the one- and two-center charge densities over complete orthonormal sets of Ψα-exponential type orbitals (Ψα-ETO α = 1,0,-1,-2,…) introduced by the author. Three-center overlap integrals of Ψα appearing in these relations are expressed through the two-center overlap integrals between Ψα-orbitals. The general formulae obtained for the charge densities are utilized for the evaluation of arbitrary multicenter–multielectron integrals occurring when the complete orthonormal sets of Ψα-ETO are used as basis functions in the Hartree–Fock–Roothaan and explicitly correlated methods. The relationships for charge densities and multicenter–multielectron integrals obtained are valid for the arbitrary quantum numbers, screening constants, and location of Ψα-orbitals.

Evaluation of Sub-Gap States in Amorphous In-Ga-Zn-O Thin Films Treated with Various Process Conditions

2014 ◽  
Vol 1633 ◽  
pp. 55-60 ◽  
Author(s):  
Kazushi Hayashi ◽  
Aya Hino ◽  
Hiroaki Tao ◽  
Yasuyuki Takanashi ◽  
Shinya Morita ◽  
...  
Keyword(s):  
Thin Films ◽  
Peak Position ◽  
Process Conditions ◽  
Charge Densities ◽  
Capacitance Voltage ◽  
Time Regime ◽  
Order Of Magnitude ◽  
Transient Spectroscopy ◽  
Gap States ◽  
Capacitance Transient

ABSTRACTIn the present study, the sub-gap states of amorphous In-Ga-Zn-O (a-IGZO) thin films treated with various process conditions have been evaluated by means of capacitance-voltage (C-V) characteristics and isothermal capacitance transient spectroscopy (ICTS). It was found that the space-charge densities of the a-IGZO decreased as the oxygen partial pressure was increased during the sputtering of a-IGZO thin films. The ICTS spectra for the 4, 8, and 12 % samples were similar and the peak positions were found to be around 1 × 10-2 s at 180 K. On the other hand, the peak position for the 20 % sample shifted to a longer time regime and was located at around 2 × 10-1 s at 180 K. The total densities of the traps for the 4, 8, and 12 % samples were calculated to be 5−6 × 1016 cm-3, while that for 20 % was one order of magnitude lower than the others. From Thermal desorption spectrometer, it was found that desorption of Zn atoms started at a temperature higher than 300 °C for the 4 % sample, while desorption of Zn was not observed for the 20 % sample. The introduction of the sub-gap states could be attributed to oxygen-rich and/or Zn-deficient defects in the a-IGZO thin films formed during thermal annealing.

scholarly journals THE FREE RADICAL BRO MINA TION OF ETHYL PYRIDAZINES: THEORETICAL STUDIES

2014 ◽  
Vol 22 (22) ◽  
pp. 53-60
Author(s):  
I. A. ADEJORO ◽  
R. O. Ogede ◽  
C. U. Ibeji ◽  
O. O. Adeboye
Keyword(s):  
Free Radical ◽  
Rapid Method ◽  
Computational Methods ◽  
Theoretical Studies ◽  
Hartree Fock ◽  
Radical Bromination ◽  
Total Energies ◽  
Pyridazine Derivatives ◽  
Semi Empirical

Theoretical studies on free radical bromination by N-bromosuccinimide were carried out on a range of ethyl-3-methoxy-pyridazine derivatives. The investigations of these reactions performed, in order to develop a convenient and rapid theoretical means of predicting selectivity. The geometry optimizations of the total energies of the reactants and the products were calculated using Semi-empirical; AMI, MNDO, PM3 e Hartree Fock, HF3- 21 G computational methods. The calculation performed using PM3 Hamiltonian gave the best qualitative predictions, thus providing a rapid method for the selectivity of the reactions used in the synthesis of novel heterocyclic analogs of neurotransmitters.

scholarly journals Investigation of the nuclear structure of 84-108Mo isotopes using Skyrme-Hartree-Fock method

2019 ◽  
Vol 13 (26) ◽  
pp. 1-11
Author(s):  
Ali A. Alzubadi
Keyword(s):  
Density Functional ◽  
Good Description ◽  
Mean Field ◽  
Nucleon Nucleon ◽  
Effective Density ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Energy Density Functional ◽  
Charge Densities ◽  
Hartree Fock

Over the last few decades the mean field approach using selfconsistentHaretree-Fock (HF) calculations with Skyrme effectiveinteractions have been found very satisfactory in reproducingnuclear properties for both stable and unstable nuclei. They arebased on effective energy-density functional, often formulated interms of effective density-dependent nucleon–nucleon interactions.In the present research, the SkM, SkM*, SI, SIII, SIV, T3, SLy4,Skxs15, Skxs20 and Skxs25 Skyrme parameterizations have beenused within HF method to investigate some static and dynamicnuclear ground state proprieties of 84-108Mo isotopes. In particular,the binding energy, proton, neutron, mass and charge densities andcorresponding root mean square radius, neutron skin thickness andcharge form factor are calculated by using this method with theSkyrme parameterizations mentioned above. The calculated resultsare compared with the available experimental data. Calculationsshow that the Skyrme–Hartree–Fock (SHF) theory with aboveforce parameters provides a good description on Mo isotopes.

Gaussian basis sets for the atoms from K through Xe

2001 ◽  
Vol 79 (2) ◽  
pp. 121-123 ◽  
Author(s):  
R Centoducatte ◽  
E VR de Castro ◽  
F E Jorge
Keyword(s):  
Key Words ◽  
Ground State ◽  
Basis Sets ◽  
Gaussian Basis Sets ◽  
Hartree Fock ◽  
Generator Coordinate ◽  
Discretization Technique ◽  
Total Energies

An improved generator coordinate Hartree-Fock (IGCHF) method is used to generate Gaussian basis sets for the atoms from K (Z = 19) through Xe (Z = 54). The Griffin-Hill-Wheeler-HF equations are integrated using the integral discretization technique. The ground state HF total energies obtained by us are compared with those calculated with the original GCHF method and with other approaches reported in the literature. The largest difference between our energy values and the corresponding ones computed with a numerical HF method is equal to 6.003 mhartree for Kr (Z = 36).Key words: improved generator coordinate Hartree-Fock method, Gaussian basis sets, total energies.

Electron impact total and ionization cross sections for Sr, Y, Ru, Pd, and Ag atoms

2013 ◽  
Vol 91 (9) ◽  
pp. 744-750 ◽  
Author(s):  
Dhanoj Gupta ◽  
Rahla Naghma ◽  
Bobby Antony
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Optical Potential ◽  
Atomic Orbital ◽  
Atomic Charge ◽  
Ionization Cross ◽  
Charge Densities ◽  
Hartree Fock ◽  
Spherical Complex ◽  
Ionization Cross Sections

Calculation of electron impact total and ionization cross sections for Sr, Y, Ru, Pd, and Ag atoms were performed using spherical complex optical potential and complex scattering potential-ionization contribution methods. The complex optical potential model is formulated from the target parameters and the atomic charge density. The spherical charge densities are in turn derived from the Roothaan–Hartree–Fock wavefunctions defining the atomic orbital of the target. In the present study cross sections are computed in the energy range from ionization threshold to 2000 eV. The results obtained are compared with other theories and measurements wherever available and were found to be quite consistent and uniform. In general, present data show an overall reasonable agreement with other results. Dependence of total cross sections on the number of target electrons and peak of ionization cross section on target parameters were also found to be consistent with previous observations.

Electrical Transport and In-Situ X-Ray Studies of the Formation of TiSi2 Thin Films on Si

1986 ◽  
Vol 77 ◽  
Author(s):  
J. C. Hensel ◽  
J. M. Vandenberg ◽  
L. F. Mattheiss ◽  
F. C. Unterwald ◽  
A. Maury
Keyword(s):  
Thin Films ◽  
Electrical Transport ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
Metallic Behavior ◽  
Distinctive Features ◽  
X Ray ◽  
Total Energies ◽  
Sputter Deposited

ABSTRACTThe formation of TiSi2 thin films on Si has been investigated by in situ x-ray diffraction and by electrical transport. The x-ray results show unequivocally that the staging proceeds through two orthorhombic polytypes of TiSi2 according to the sequence: sputter-deposited metallic Ti films on Si (001) → TiSi2 (C49 structure) → TiSi2 (C54 structure), with no evidence of lower suicides. Electrical transport shows metallic behavior for all phases and distinctive features in the annealing curves which correlate with the structural transformations. Most importantly, the resistivity, characteristically very high for the C49 phase, undergoes a precipitous drop at the C49 → C54 transition. Total energies for both phases are calculated and, consistent with the occurrence of a structural phase transformation, are found not to differ appreciably.

Calculations of Perovskite Surface Relaxation

2000 ◽  
Vol 654 ◽  
Author(s):  
E. Heifets ◽  
E.A. Kotominc ◽  
R.I. Eglitisc ◽  
R.E. Cohen
Keyword(s):  
Thin Films ◽  
Surface Energy ◽  
Ab Initio ◽  
Shell Model ◽  
Electron Correlation ◽  
Surface Relaxation ◽  
Hartree Fock ◽  
Semi Empirical ◽  
Good Agreement ◽  
Correlation Corrections

AbstractThe (100) and (110) surface relaxations are calculated for SrTiO3 and BaTiO3 perovskite thin films by means of a semi-empirical shell model (SM) for different surface terminations. Our SM results for the (100) surface structure are in good agreement with our present ab initio Hartree-Fock calculations with electron correlation corrections, previous ab initio pseudopotential calculationsand LEED experiments. The surface energy for the Ba-, Sr-, TiO- terminated (110) surfaces is found much larger than that for the (100) one. In contrast, the surface energy for the asymmetric O-termination, where outermost O atoms are strongly on-plane displaced, is the lowest for all (110) terminations and thus the most stable.

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