Adiabatic connection/fluctuation-dissipation

Exchange-correlation Energy-functional from Adiabatic Connection Fluctuation-dissipation Theorem... 

Adiabatic-connection fluctuation-dissipation theorem allows one to express the exchange-correlation energy-functional by means of imaginary-frequency density response function ( A) of the system with the scaled Coulomb potential (A/ r — r )11,13 ... 

Fuchs M, Gonze X (2002) Accurate density functionals Approaches using adiabatic-connection fluctuation-dissipation theorem, Phys. Rev. B, 65 235109... 

The first-principle method is being developed for systems with long-range dispersion forces. There are two ways to include dispersion forces in first-principle calculations. A semiempirical van der Waals interaction can be taken into account in ab initio calculations. It is realized by using the Lenard-Jones potential of the form (11.26). The second approach is based on the adiabatic connection fluctuation-dissipation theorem. This theory includes seamless long-range dispersion forces... 

Harl, J. and Kresse, G. (2008) Cohesive energie curves for noble gas solids calculated by adiabatic connection fluctuation-dissipation theory. Phys. Rev. B, 77, 045135-1-045136-8. 

By using linear-response theories, dispersion interactions can be calculated directly in the framework of the Kohn-Sham method. The adiabatic connection/fluctuation-dissipation theorem (AC/FDT) method is a linear-response theory for exactly calculating dispersion interactions within the framework of the Kohn-Sham method (Langreth and Perdew 1975). In this AC/FDT method, electron correlation is calculated as the energy response quantity for the spontaneous fluctuations of electronic motions coming from the perturbation of the interelectronic interactions, as follows ... 

MBPT provides several ways to obtain each of the different contributions to the ground-state energy Perhaps the best known, owing to its role in the construction of xc energy functionals, is the expression based on the adiabatic-connection-fluctuation-dissipation (ACFD) theorem [75,76]... 

To construct the ground-state energy functional we use the long known adiabatic connection fluctuation-dissipation (ACFD) formula ... 

Approaches Using the Adiabatic-Connection Fluctuation-Dissipation Theorem. 

The last few years have seen some very exciting developments on yet higher rungs of the ladder of exchange-correlation functionals. In particular, approaches that explicitly account for correlation have emerged, such as the random phase approximation (RPA) within the adiabatic-connection-fluctuation-dissipation theorem. Very recently, RPA has been applied to solids and surfaces with some very encouraging results (e.g., [45-49]). 

The starting point for the proposed new approach is an exact formula [238], [239], based on the adiabatic connection formula and the zero-temperature fluctuation-dissipation theorem, relating the groundstate xc energy to the inter-... 

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