Density-functional formalism: Sources of error in local-density approximations

1985 ◽  
Vol 55 (1) ◽  
pp. 107-110 ◽  
Author(s):  
R. O. Jones ◽  
O. Gunnarsson
Keyword(s):  
Density Functional ◽  
Local Density ◽  
Functional Formalism ◽  
Sources Of Error ◽  
Local Density Approximations

Magnetic Properties of Embedded Rh Clusters in Ni Matrix

1995 ◽  
Vol 384 ◽  
Author(s):  
Zhi-Qiang Li ◽  
Yuichi Hashi ◽  
Jing-Zhi Yu ◽  
Kaoru Ohno ◽  
Yoshiyuki Kawazoe
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Magnetic Moments ◽  
Functional Formalism ◽  
Rhodium Clusters ◽  
Spin Polarized ◽  
Local Density Functional

ABSTRACTThe electronic structure and magnetic properties of rhodium clusters with sizes of 1 - 43 atoms embedded in the nickel host are studied by the first-principles spin-polarized calculations within the local density functional formalism. Single Rh atom in Ni matrix is found to have magnetic moment of 0.45μB. Rh13 and Rhl 9 clusters in Ni matrix have lower magnetic moments compared with the free ones. The most interesting finding is tha.t Rh43 cluster, which is bulk-like nonmagnetic in vacuum, becomes ferromagnetic when embedded in the nickel host.

Electronic bonding characteristics of hydrogen in bcc iron: Part I. Interstitials

1996 ◽  
Vol 11 (9) ◽  
pp. 2206-2213 ◽  
Author(s):  
Yoshio Itsumi ◽  
D. E. Ellis
Keyword(s):  
Density Functional ◽  
Local Density ◽  
Lattice Relaxation ◽  
Experimental Result ◽  
Functional Formalism ◽  
Discrete Variational Method ◽  
Bcc Iron ◽  
Bond Strengths ◽  
Bonding Characteristics ◽  
Structure Calculations

Electronic structure calculations were carried out for bcc iron (Fe) clusters with or without hydrogen (H), and also involving a vacancy, using the self-consistent Discrete Variational method (DV-Xα) within the local density functional formalism. Bonding characteristics investigated show the following: (i) Interstitial H notably decreases interatomic Fe–Fe bond strengths, but acts over a small distance (within 0.3 nm). (ii) In the perfect Fe lattice field, interstitial H feels a repulsive force at any site. As a result of lattice relaxation, volume expansion may be expected. (iii) H in combination with a vacancy prefers a position shifted from the octahedral site toward the vacancy. This is fairly consistent with an experimental result.

scholarly journals VIBRATIONAL MODES IN SMALL Agn, Aun CLUSTERS: A FIRST PRINCIPLE CALCULATION

2009 ◽  
Vol 23 (31) ◽  
pp. 5819-5834 ◽  
Author(s):  
OLCAY ÜZENGI AKTÜRK ◽  
OĞUZ GÜLSEREN ◽  
MEHMET TOMAK
Keyword(s):  
Normal Mode ◽  
Density Functional ◽  
Local Density ◽  
Scanning Tunneling ◽  
Generalized Gradient ◽  
Functional Formalism ◽  
First Principle Calculation ◽  
Pseudopotential Calculations ◽  
Normal Mode Calculations ◽  
Small Clusters

Although the stable structures and other physical properties of small Ag n and Au n, were investigated in the literature, phonon calculations are not done yet. In this work, we present plane-wave pseudopotential calculations based on density-functional formalism. The effect of using the generalized gradient approximation (GGA) and local density approximation (LDA) to determine the geometric and electronic structure and normal mode calculations of Ag n and Au n, is studied up to eight atoms. Pure Au n and Ag n clusters favor planar configurations. We calculated binding energy per atom. We have also calculated the normal mode calculations and also scanning tunneling microscope (STM) images for small clusters for the first time.

SURFACE SENSITIVITY OF VERY LOW ENERGY ELECTRONS

1999 ◽  
Vol 06 (05) ◽  
pp. 631-633 ◽  
Author(s):  
I. BARTOŠ ◽  
W. SCHATTKE
Keyword(s):  
Density Functional ◽  
Local Density ◽  
Quantitative Description ◽  
Low Energy ◽  
Imaginary Component ◽  
Functional Formalism ◽  
Self Energy ◽  
Surface Sensitivity ◽  
Escape Depth ◽  
Low Energies

The surface sensitivity of electron diffraction and of electron spectroscopies is determined by the imaginary component of the electron self-energy. In crystals, the energy and direction dependence of the electron attenuation and of the escape depth should be taken into account at very low energies. Strong anisotropy of the electron attenuation has been obtained around 20 eV from peak shapes in VLEED intensity profiles from (111) transition metal surfaces. Extension of the local density approximation in the density functional formalism provides quantitative description of the electron self-energy. The one-step model of angular resolved photoemission incorporating the self-energy predicts a strong energy and angle dependence of the escape depth of low energy photoelectrons emitted from GaAs(110).

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