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Related papers: Density-matrix functionals from Greens functions

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We present a generalization of the Li, Nunes and Vanderbilt density-matrix method to the case of a non-orthogonal set of basis functions. A representation of the real-space density matrix is chosen in such a way that only the overlap…

Condensed Matter · Physics 2009-10-22 R. W. Nunes , David Vanderbilt

A scheme within density functional theory is proposed that provides a practical way to generalize to unrestricted geometries the method applied with some success to layered geometries [H. Rydberg, et al., Phys. Rev. Lett. 91, 126402…

Materials Science · Physics 2009-11-10 M. Dion , H. Rydberg , E. Schroder , D. C. Langreth , B. I. Lundqvist

I review the quantum theory of the electron moving in a random environment. First, the quantum mechanics of individual particles scattered on a random potential is discussed. The quantum-mechanical description is extended to many-body…

Disordered Systems and Neural Networks · Physics 2021-09-13 Václav Janiš

We study both static and transport properties of model quantum dots, employing density functional theory as well as (numerically) exact methods. For the lattice model under consideration the accuracy of the local-density approximation…

Mesoscale and Nanoscale Physics · Physics 2011-04-11 S. Schenk , P. Schwab , M. Dzierzawa , U. Eckern

We present a new density-matrix functional within the recently introduced framework for tensor-product expansions of the two-particle density matrix. It performs well both for the homogeneous electron gas as well as atoms. For the…

Materials Science · Physics 2009-11-07 Gábor Csányi , Stefan Goedecker , T. A. Arias

We propose and compare different strategies to construct dynamic density functional theories (DDFTs) for inhomogeneous polymer systems close to equilibrium from microscopic simulation trajectories. We focus on the systematic construction of…

Soft Condensed Matter · Physics 2020-09-29 Sriteja Mantha , Shuanhu Qi , Friederike Schmid

Mesoscopic theory for soft-matter systems that combines density functional and statistical field theory is derived from the microscopic theory by a systematic coarse-graining procedure. Within the framework of this theory we obtain the…

Soft Condensed Matter · Physics 2013-05-29 A. Ciach

We give graphical rules, based on earlier work for the functional Schrodinger equation, for constructing the density matrix for scalar and gauge fields at finite temperature T. More useful is a dimensionally-reduced effective action (DREA)…

High Energy Physics - Theory · Physics 2009-11-07 C. A. A. de Carvalho , John M. Cornwall , A. J. da Silva

The effective action for the charge density and the photon field is proposed as a generalization of the density functional. A simple definition is given for the density functional, as the functional Legendre transform of the generator…

Strongly Correlated Electrons · Physics 2009-11-07 J. Polonyi , K. Sailer

A density functional theory is developed for fermions in one dimension, interacting via a delta-function. Such systems provide a natural testing ground for questions of principle, as the local density approximation should work well for…

Other Condensed Matter · Physics 2007-05-23 R. J. Magyar , K. Burke

Representing spectral densities, real-frequency, and real-time Green's functions of continuous systems by a small discrete set of complex poles is an ubiquitous problem in condensed matter physics, with applications ranging from quantum…

Strongly Correlated Electrons · Physics 2025-06-04 Lei Zhang , André Erpenbeck , Yang Yu , Emanuel Gull

Rigorous mathematical foundations of density functional theory are revisited, with some use of infinitesimal (nonstandard) methods. A thorough treatment is given of basic properties of internal energy and ground-state energy functionals…

Other Condensed Matter · Physics 2016-06-30 Paul E. Lammert

Using a path integral approach and bosonization, we calculate the low energy asymptotics of the one particle Green's function for a ``magnetically incoherent'' one dimensional strongly interacting electron gas at temperatures much greater…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Gregory A. Fiete , Leon Balents

Classical density functional theory (DFT) is a statistical mechanical theory for calculating the density profiles of the molecules in a liquid. It is widely used, for example. to calculate the density distribution of the molecules in the…

Statistical Mechanics · Physics 2015-07-08 Adam P. Hughes , Uwe Thiele , Andrew J. Archer

The basic mathematical properties of Green's functions used in statistical mechanics as well as the equations defining these functions and the techniques of solving these equations are reviewed. An approach is presented called the…

Statistical Mechanics · Physics 2007-05-23 V. I. Yukalov

A nonperturbative electron transfer rate theory is developed based on the reduced density matrix dynamics, which can be evaluated readily for the Debye solvent model without further approximation. Not only does it recover for reaction rates…

Quantum Physics · Physics 2007-05-23 Ping Han , Rui-Xue Xu , Baiqing Li , Jian Xu , Ping Cui , Yan Mo , YiJing Yan

We establish necessary and sufficient conditions for the N-representability of the universal one-electron reduced density matrix functional. Functionals satisfying these conditions are guaranteed to yield variational upper bounds on the…

Quantum Physics · Physics 2026-04-08 Jannis Erhard , Paul W. Ayers

The Hubbard model is investigated in the framework of lattice density functional theory (LDFT). The single-particle density matrix $\gamma_{ij}$ with respect the lattice sites is considered as the basic variable of the many-body problem. A…

Strongly Correlated Electrons · Physics 2009-11-10 R. Lopez-Sandoval , G. M. Pastor

DFT calculations yield useful ground-state energies and densities, while Green's function techniques (such as $GW$) are mostly used to produce spectral functions. From the Galitskii-Migdal formula, we extract the exchange-correlation of DFT…

Chemical Physics · Physics 2024-03-13 Steven Crisostomo , E. K. U. Gross , Kieron Burke

The subject of this study is the exchange-correlation-energy functional of reduced density matrix functional theory. Approximations of this functional are tested by applying them to the homogeneous electron gas. We find that two…

Materials Science · Physics 2011-01-14 N. N. Lathiotakis , N. Helbig , E. K. U. Gross