| | 1 | Author
| F. Bell, Th Tschentscher, J. R. Schneider, A. J. Rollason | Requires cookie* | | | Title
| Electron Momentum Densities by (y, e y)-Spectroscopy  | | | | Abstract
| We report coincidence measurements of inelastically scattered 148 keV photons and the recoil electrons generated within thin Al and Cu foils. We have analyzed both the Doppler broadening of the scattered photon intensity and the angular correlation of the recoil electron. This corresponds to different scans through the three-dimensional electron momentum density of the target. Estimates of the triple-differential cross-section for Compton scattering are given. The experiment was per-formed with synchrotron radiation from a bending magnet of the DORIS storage ring at DESY, Hamburg. | | | |
Reference
| Z. Naturforsch. 48a, 273—278 (1993); received October 8 1991 | | | |
Published
| 1993 | | | |
Keywords
| Electron momentum densities, Compton scattering, Synchrotron radiation | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/48/ZNA-1993-48a-0273.pdf | | | | Identifier
| ZNA-1993-48a-0273 | | | | Volume
| 48 | |
| 2 | Author
| SudhirA. Kulkarni, ShridharR. Gadre | Requires cookie* | | | Title
| On the Topography of Electron Momentum Densities of Linear Molecules | | | | Abstract
| A topographical study of the electron momentum density (EMD) of some linear molecules is presented with special emphasis on the bond-directionality principle. A new approach to the bond-directionality (BD) principle has been proposed. This is based on the analysis of curvatures of critical points at p = 0 and elsewhere on the bonding axis. The linear molecules are classified into three broad categories: those which fully obey or disobey the BD principle as well as those which satisfy it only partly. The Laplacian of the EMD at p = 0 has been associated with the quality of the wavefunction via the electron density in the tail region. Also, the similarity in the critical structure of both the EMD and the spherically averaged EMD at the origin is brought out. | | | |
Reference
| Z. Naturforsch. 48a, 145—150 (1993); received January 3 1992 | | | |
Published
| 1993 | | | |
Keywords
| Electron momentum densities, Eigenvalues, Critical points, Topography, Bond direc-tionality | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/48/ZNA-1993-48a-0145.pdf | | | | Identifier
| ZNA-1993-48a-0145 | | | | Volume
| 48 | |
| 3 | Author
| Claudia Blaas, Josef Redinger, Raimund Podloucky, Peter Jonas, Peter Schattschneider | Requires cookie* | | | Title
| Calculation of Compton Profiles Using a Multipole Expansion of the Momentum Density | | | | Abstract
| A practical method for the calculation of Compton profiles for cubic systems with O and O h symmetry is presented that is based on a multipole expansion of the electron momentum density (EMD) in terms of cubic harmonics. The central quantities, the expansion coefficients, are deter-mined by a Gaussian-type integration (special directions) over the angular coordinates. From these coefficients the coefficients of an analogous expansion of the Compton profile can be directly calculated, establishing a transparent relationship between the electron momentum density and the Compton profile. This direct relationship offers the possibility of tracing back Compton-profile anisotropics to EMD anisotropics more easily, as demonstrated for MgO and FeAl. | | | |
Reference
| Z. Naturforsch. 48a, 198—202 (1993); received December 24 1991 | | | |
Published
| 1993 | | | |
Keywords
| Compton profile, Electron momentum density, Multipole expansion, MgO, FeAl | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/48/ZNA-1993-48a-0198.pdf | | | | Identifier
| ZNA-1993-48a-0198 | | | | Volume
| 48 | |
| 4 | Author
| M. A. Coplan, J. H. Moore, J. A. Tossell | Requires cookie* | | | Title
| (e, 2 e)-Spectroscopy and the Electronic Structure of Molecules. A Short Review with Selected Examples | | | | Abstract
| The simple plane wave target Hartree-Fock impulse approximation for the (e, 2e) reaction is developed. One result of the approximation is the separation of the expression for the (e, 2e) cross-section into a kinematic factor and a structure factor that contains all of the information about the target. When the target is a molecule, the structure factor can be further separated into atomic terms and a geometric term. This is illustrated for a simple one-electron homonuclear diatomic molecule. Three examples of the application of (e, 2e) spectroscopy to systems of chemical interest are given. They are borazine (inorganic benzene), the methyl siloxanes and the inorganic complex trimethylamine boron trifluoride. | | | |
Reference
| Z. Naturforsch. 48a, 358—370 (1993); received January 30 1992 | | | |
Published
| 1993 | | | |
Keywords
| (e, 2e)-Spectroscopy, Electron momentum spectroscopy, Electron momentum density, Electronic structure | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/48/ZNA-1993-48a-0358.pdf | | | | Identifier
| ZNA-1993-48a-0358 | | | | Volume
| 48 | |
| 5 | Author
| Erich Weigold | Requires cookie* | | | Title
| Recent Advances in Electron Momentum Spectroscopy | | | | Abstract
| The flexibility of the (e, 2e) technique or "electron momentum spectroscopy" (EMS) in obtaining information on the electronic structure of atoms, molecules, and solids is demonstrated. High-resolution EMS measurements for argon, including the first measurements of momentum profiles belonging to the 2 P° and 2 D e -manifolds, are used to demonstrate the technique for atomic targets. The d-wave transitions in argon are entirely due to initial-state correlations. The first (e, 2e) measure-ments on an excited target, and also on an oriented target, are discussed. Sodium atoms are pumped to the m, = +1 state of the excited 3p-state by cr + -light from a laser. The (e, 2e) measurements on this excited state are in excellent agreement with the momentum density given by the 3p (m, — 1) Hartree-Fock wavefunction. The recent measurements of the valence-electron momentum distribu-tions for ethyne, as well as some earlier results for water, are used as an example of the application of EMS to the study of molecules. The application of the EMS technique to measure spectral momentum densities in condensed-matter targets is demonstrated by some recent results on amor-phous carbon. | | | |
Reference
| Z. Naturforsch. 48a, 371—389 (1993); received March 28 1992 | | | |
Published
| 1993 | | | |
Keywords
| Electron momentum densities, Electron momentum spectroscopy, Wavefunction map-ping, Binding energies | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/48/ZNA-1993-48a-0371.pdf | | | | Identifier
| ZNA-1993-48a-0371 | | | | Volume
| 48 | |
|
