EXCHANGE-CORRELATION FUNCTIONALS FROM THE IDENTICAL-PARTICLE ORNSTEIN-ZERNIKE EQUATION: BASIC FORMULATION AND NUMERICAL ALGORITHMS

2010 ◽  
Vol 24 (25n26) ◽  
pp. 5115-5127 ◽  
Author(s):  
ROGELIO CUEVAS-SAAVEDRA ◽  
PAUL W. AYERS
Keyword(s):  
Correlation Function ◽  
Correlation Energy ◽  
Identical Particle ◽  
Numerical Algorithms ◽  
Direct Correlation Function ◽  
Correlation Integral ◽  
Exchange Correlation ◽  
Theory Of Liquids ◽  
Correlation Hole ◽  
Particle Nature

We adapt the classical Ornstein-Zernike equation for the direct correlation function of classical theory of liquids in order to obtain a model for the exchange-correlation hole based on the electronic direct correlation function. Because we explicitly account for the identical-particle nature of electrons, our result recovers the normalization of the exchange-correlation hole. In addition, the modified direct correlation function is shorted-ranged compared to the classical formula. Functionals based on hole models require six-dimensional integration of a singular integrand to evaluate the exchange-correlation energy, and we present several strategies for efficiently evaluating the exchange-correlation integral in a numerically stable way.

Finite-T correlations and free exchange-correlation energy of quasi-one-dimensional electron gas

2018 ◽  
Vol 32 (05) ◽  
pp. 1850060 ◽  
Author(s):  
Vinayak Garg ◽  
Akariti Sharma ◽  
R. K. Moudgil
Keyword(s):  
Correlation Function ◽  
Pair Correlation Function ◽  
Correlation Energy ◽  
Pair Correlation ◽  
Electron Gas ◽  
Dimensional Electron ◽  
One Dimensional ◽  
Exchange Correlation ◽  
Dimensional Electron Gas ◽  
Plasmon Dispersion

We have studied the effect of temperature on static density–density correlations and plasmon excitation spectrum of quasi-one-dimensional electron gas (Q1DEG) using the random phase approximation (RPA). Numerical results for static structure factor, pair-correlation function, static density susceptibility, free exchange-correlation energy and plasmon dispersion are presented over a wide range of temperature and electron density. As an interesting result, we find that the short-range correlations exhibit a non-monotonic dependence on temperature T, initially growing stronger (i.e. the pair-correlation function at small inter-electron spacing assuming relatively smaller values) with increasing T and then weakening above a critical T. The cross-over temperature is found to increase with increasing coupling among electrons. Also, the [Formula: see text] peak in the static density susceptibility [Formula: see text] at T = 0 K smears out with rising T. The free exchange-correlation energy and plasmon dispersion show a significant variation with T, and the trend is qualitatively the same as in higher dimensions.

Inelastic scattering at surfaces and interfaces

1986 ◽  
Vol 44 ◽  
pp. 392-393
Author(s):  
R. H. Ritchie ◽  
A. Howie
Keyword(s):  
Inelastic Scattering ◽  
Surface Properties ◽  
Correlation Energy ◽  
Condensed Matter ◽  
Charged Particles ◽  
Condensed Matter Physics ◽  
Optical Phonons ◽  
Exchange Correlation ◽  
Surfaces And Interfaces ◽  
Inelastic Interactions

An important part of condensed matter physics in recent years has involved detailed study of inelastic interactions between swift electrons and condensed matter surfaces. Here we will review some aspects of such interactions.Surface excitations have long been recognized as dominant in determining the exchange-correlation energy of charged particles outside the surface. Properties of surface and bulk polaritons, plasmons and optical phonons in plane-bounded and spherical systems will be discussed from the viewpoint of semiclassical and quantal dielectric theory. Plasmons at interfaces between dissimilar dielectrics and in superlattice configurations will also be considered.

Exchange-Correlation Energy Densities and Response Potentials: Connection Between Two Definitions and Analytical Model for the Strong-Coupling Limit of a Stretched Bond

2019 ◽  
Author(s):  
S. Giarrusso ◽  
Paola Gori-Giorgi
Keyword(s):  
Density Functional Theory ◽  
Strong Coupling ◽  
Density Functional ◽  
Correlation Energy ◽  
Order Term ◽  
Strong Coupling Limit ◽  
Local Form ◽  
Coupling Constant ◽  
Functional Theory ◽  
Exchange Correlation

We analyze in depth two widely used definitions (from the theory of conditional probablity amplitudes and from the adiabatic connection formalism) of the exchange-correlation energy density and of the response potential of Kohn-Sham density functional theory. We introduce a local form of the coupling-constant-dependent Hohenberg-Kohn functional, showing that the difference between the two definitions is due to a corresponding local first-order term in the coupling constant, which disappears globally (when integrated over all space), but not locally. We also design an analytic representation for the response potential in the strong-coupling limit of density functional theory for a model single stretched bond.<br>

Relativistic exchange-correlation energy functional: Gauge dependence of the no-pair correlation energy

1998 ◽  
Vol 58 (2) ◽  
pp. 993-1000 ◽  
Author(s):  
A. Facco Bonetti ◽  
E. Engel ◽  
R. M. Dreizler ◽  
I. Andrejkovics ◽  
H. Müller
Keyword(s):  
Correlation Energy ◽  
Pair Correlation ◽  
Energy Functional ◽  
Exchange Correlation ◽  
Gauge Dependence

The gas-liquid surface of the penetrable sphere model. II

1978 ◽  
Vol 358 (1694) ◽  
pp. 267-280 ◽  
Keyword(s):  
Surface Tension ◽  
Correlation Function ◽  
Liquid Surface ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Intermolecular Potential ◽  
Direct Correlation Function ◽  
Sphere Model ◽  
One Dimensional

The direct correlation function between two points in the gas-liquid surface of the penetrable sphere model is obtained in a mean-field approximation. This function is used to show explicitly that three apparently different ways of calculating the surface tension all lead to the same result. They are (1) from the virial of the intermolecular potential, (2) from the direct correlation function, and (3) from the energy density. The equality of (1) and (2) is shown analytically at all temperatures 0 < T < T c where T c is the critical temperature; the equality of (2) and (3) is shown analytically for T ≈ T c , and by numerical integration at lower temperatures. The equality of (2) and (3) is shown analytically at all temperatures for a one-dimensional potential.

Ornstein–Zernike equation for the direct correlation function with a Yukawa tail

1975 ◽  
Vol 62 (11) ◽  
pp. 4247-4259 ◽  
Author(s):  
Douglas Henderson ◽  
George Stell ◽  
Eduardo Waisman
Keyword(s):  
Correlation Function ◽  
Direct Correlation Function
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