
	Where results make sense

Topic: Density functional theory

Related Topics

Computational chemistry

GAMESS

Computational chemistry

PLATO (Package for Linear Combination of Atomic Orbitals)

Quantum mechanics

Quantum chemistry

Propeller engine

Drug design

QSPR

Chemical conformation

New Buffalo, Pennsylvania

Density

Lyndon, Illinois

White Oak, Ohio

Derek Quigley

In the News (Thu 31 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	2.5 Density functional theory
		Note that in the bonding regions between silicon atoms, the error in the exchange energy density tends to cancel with the error in the correlation energy density.
		a functional of the density and its gradient:
		The development of improved functionals is currently a very active area of research and although incremental improvements are likely, it is far from clear whether the research will be successful in providing the substantial increase in accuracy desired.
	www.physics.uc.edu /~pkent/thesis/pkthnode15.html (925 words)

	Density functional theory - Biocrawler (Site not responding. Last check: )
		Density functional theory (DFT) is one of the most popular approaches to quantum mechanical many-body electronic structure calculations of molecular and condensed matter systems.
		The main objective of density functional theory is to replace the many-body electronic wavefunction with the electronic density as the basic quantity.
		Although density functional theory has its conceptual roots in the Thomas-Fermi model, DFT was not put on a firm theoretical footing until the Hohenberg-Kohn (HK) theorem which demonstrates the existence of a one-to-one mapping between the ground state electron density and the ground state wavefunction of a many-particle system.
	www.biocrawler.com /encyclopedia/Density_functional_theory (1431 words)

	Density Functional Theory (Site not responding. Last check: )
		Density functional theory is an extremely successful approach for the description of ground state properties of metals, semiconductors, and insulators.
		Basics of Density Functional Theory.'' This section contains a talk that I gave at the Nuclear Physics Seminar at OSU and at the physics colloquium of the University of Braunschweig, Germany.
		The section Exact-Exchange Density Functional Theory and Quasiparticle Calculations discusses such density functional schemes and their relevance for quasiparticle calculations, that is, computational many-body theory.
	www.physics.ohio-state.edu /~aulbur/dft.html (396 words)

	Density functional theory: Definition and Links by Encyclopedian.com
		Municipalities-of-V%E4s...the linear functional L on polynomials in y defined by $L(y^n)=b-n$ ....Rota used umbral methods to establish the recursion formula satisfied by the Bell numbers....
		Density functional theory (DFT) is a formally exact re-writing of quantum mechanics with the electron density ρ as the basic variable instead of the wavefunction.
		The reduced computational cost of this approach lead to DFT becoming the most popular method of quantum chemistry from the mid-1990s onwards.
	www.encyclopedian.com /de/Density-functional-theory.html (226 words)

	Master Program Computational Science: 2nd-Layer Template
		Density Functional Theory (DFT) is a general approach to the ab initio description of quantum many-particle systems, in which the original many-body problem is rigorously recast in the form of an auxiliary single-particle problem (for an overview see [1]).
		The exact density functional representation of this crucial quantity of DFT is not known, the derivation of suitable approximations being the major task in DFT.
		In addition, density functional methods are used to study the structure and dynamics of molecules, clusters and solids.
	www.th.physik.uni-frankfurt.de /~engel/dft.html (379 words)

	Surface Science in Cambridge
		DFT succeeds by abdicating all knowledge of the actual wavefunction, and concentrating instead on a much simpler quantity: the density of electrons distributed throughout the solid (see figure).
		Nowadays, DFT is regularly used to solve problems relating to semiconducting materials, for applications in the fields of electronics and optics.
		Whilst a particular theory may be self-consistent, predictive and beautiful, it must always be subject to close comparison with the "ugly truth" of experiment if it is to gain acceptance amongst the wider scientific community*.
	www-dak.ch.cam.ac.uk /DFT.html (398 words)

	Theory Continued page 3
		Calabi-Yau manifolds appear in the theory because in passing from the 10-dimensional space time to a physically realistic description in four dimension, string theory requires that the additional 6-dimensional space is to be a Calabi-Yau manifold.
		In General Relativity, the density of matter and the stress in it are determined equal to a certain combination of derivaties of Christoffel symbols.
		Any function f (defined at point q) defines a 1-form at q, the gradient of f, wherein the argument vector takes the directional derivative of the function, and the coordinate functions define a basis of all the 1-forms, notated dx[i] (i = 1..n).
	www.superstringtheory.fanspace.com /custom4.html (3489 words)

	[No title]
		*Density of states derivable from assumption that, for high quantum numbers, the number of distinct E levels for E
		* This is the Thomas-Fermi Theory of the atom
		The total energy of a system can be expressed as a functional of the density and this functional is minimized by the ground state density.
	www.sdsc.edu /~kimb/dft_lecture.html (1259 words)

	Density functional theory
		Density functional theory is a totally different approach, where the system is characterised by its electron density, rather than a wave function.
		The last term, however, is a general functional for the exchange and correlation energy, not present in the Hartree-Fock method.
		One of the problems with density functional theory is that there is no clear way to improve the accuracy since the exact functional is not known and thus, the development relies on intuition and comparison with experimental results.
	www-rcf.usc.edu /~molsson/PhD/Thesis/node8.html (255 words)

	DFTEM 2006 - Vienna/Austria - bringing together two communites
		This three-day conference will focus on Density Functional Theory (DFT) and Transmission Electron Microscopy (TEM) with the intention of bringing together these two communites.
		The conference is dedicated to Karlheinz Schwarz (DFT) and Bernard Jouffrey (TEM) on the occasion of their respective birthdays, which we will celebrate at the conference dinner.
		The inverse dielectric function - theoretical approaches and contributions to theory from experiment
	www.physics.at /dftem2006 (501 words)

	[转帖]Obituary : Density Functional Theory @ 『基础理论』 (Site not responding. Last check: )
		University of Nottingham, Nottingham, UK Density Functional Theory, or DFT as she is more commonly known, was born during 1927, in the immediate aftermath of the Second Quantum Revolution.
		This was the breakthrough that allowed Density Functional models to aspire to the status of theories and earned Walter Kohn a share of the 1998 Nobel Prize for chemistry.
		That is, although we now know that, in theory, DFT can extract as much information from r(r) as her brother can from Y (r 1, r 2,...
	ctc.xmu.edu.cn /cgi-bin/topic.cgi?forum=5&topic=457&show=325 (1490 words)

	Density Functional Theory - nCyclopedia
		Density Functional Theory (DFT) postulates that the energy of a molecule can be calculated from the electron density rather than the wave function.
		The electron density requires less computational resources to determine than the wave function, so use of DFT has become a popular approach.
		In this case, the exact density functional is not known exactly.
	nanotitan.com /nCyclopedia/densityFunctionalTheory.htm (110 words)

	The Book Pl@ce: Title Detail
		Among these methods is density functional theory (DFT), which permits one to solve the equations of quantum mechanics more efficiently than with any related method.
		The present volume represents the most comprehensive summary currently available in density functional theory and its applications in chemistry from atomic physics to molecular dynamics.
		DFT is currently being used by more than fifty percent of computational chemists.
	www.thebookplace.com /bookplace/display.asp?K=182052053082158&m=7&dc=20&mw=1&st_01=Erkki&sf_01=CAUTHOR (443 words)

	Density-Functional Theory (Site not responding. Last check: )
		The LC functional proposes to split the electron repulsion into a short-range part to be treated by DFT and a long-range part to be treated by HF.
		The calculated results of the long-range correction scheme are found to support a previous argument that the lack of the long-range interactions in conventional exchange functionals may be responsible for the underestimation of 4s-3d interconfigurational energies of the first-row transition metals and for the overestimation of the longitudinal polarizabilities of pi-conjugated polyenes in DFT calculations.
		A Kohn-Sham implementation of this functional is constructed and the parameters within the functional are adjusted to minimize the difference between the theoretical and the experimental data for a large set of atomic and molecular systems.
	www-ledss.ujf-grenoble.fr /PERSONNEL/LEDSS7/casida/CompChem/DFT.html (5589 words)

	Scalable Localizable Density Functional Theory, Computational Science Center (CSC)
		Density Functional Theory (DFT) has been shown to yield accurate total energies, charge, and spin densities in molecules and crystalline solids but has been limited in the size system that can be treated.
		The density functional equations consist of coupled Schrodinger and Poisson equations, which must be solved self consistently.
		This scheme is possible because the charge density (more generally, the density matrix) is localized in space even when the eigenfunctions are not [6].
	www.bnl.gov /csc/projects/Basic_Energy/DensityFunctionalTheory/default.asp (757 words)

	Density-Functional Theory
		The system may range in complexity from a single atom to a complex system such as the gas molecules shown in the Figure, together with the atoms of the solid surface on which they are about to be adsorbed and where they will react with one another, guided by the total energy.
		However, the key functional, which describes the total energy of the electrons as a functional of their density, is not known exactly: the part of it which describes electronic exchange and correlation has to be approximated in practical calculations.
		"Density-polarisation functional theory of the response of a periodic insulating solid to an electric field", X. Gonze, P. Ghosez and R.W. Godby, Phys.
	www-users.york.ac.uk /~rwg3/resint_dft.html (409 words)

	Fast Density-Functional-Theory Calculation With Q-Chem Program
		DFT (Density functional Theory) is an essential tool in the molecular modeling, especially for studies in biology and nanotechnology.
		The cubic grid is much less dense in the vicinity of nuclei than the atom-centered grid and the computation on the former is shown to be much more efficient than on the latter.
		The extension to DFT functionals with generalized gradient approximation is also briefly discussed.
	www.nsti.org /Nanotech2006/showabstract.html?absno=344 (255 words)

	CiteULike: Linking entanglement and quantum phase transitions via density functional theory (Site not responding. Last check: )
		Density functional theory (DFT) is shown to provide a novel conceptual and computational framework for entanglement in interacting many-body quantum systems.
		DFT can, in particular, shed light on the intriguing relationship between quantum phase transitions and entanglement.
		We use DFT concepts to express entanglement measures in terms of the first or second derivative of the ground state energy.
	www.citeulike.org /user/wnoise/article/471841 (288 words)

	Density Functional Theory - Self Consistent Field Module
		It assumes a charge density, and approximations are made for the Hamiltonian (the exchange correlation functional); in contrast with the traditional ab initio molecular orbital method that assumes an exact Hamiltonian and chooses approximations to the wavefunction [52].
		The Gaussian-basis DFT method in NWChem breaks the Hamiltonian down into the same basic one-electron and two-electron components as do traditional Hartree-Fock methods, with the two-electron component further reduced to a Coulomb term and an exchange-correlation term.
		DFT is really distinguished from traditional methods, however, by the treatment of the exchange-correlation term.
	www.dl.ac.uk /TCSC/Subjects/Parallel_Applications/benchmarks/benchmarks/node42.html (868 words)

	The Book Pl@ce: Title Detail (Site not responding. Last check: )
		The 8th International Conference on the Applications of Density Functional Theory to Chemistry and Physics, held in Rome, Italy, on 6-10 September 1999, gathered chemists and physicists to present and discuss state-of-the-art methodological developments and applications of density functional theory (DFT) to increasingly complex systems.
		The scientists shared their knowledge and experience in DFT, enabling them to face the challenges posed by the needs of high level modeling and simulation in their disciplines.
		The growing use of DFT in studying organic, inorganic and organometallic molecules, clusters and solids provided the basis for the success of the conference, whose main contributions are collected in this invaluable book.
	www.bookends.co.uk /bookplace/display.asp?K=183341720612653&m=102&dc=108&mw=1&st_01=Vincenzo&sf_01=CAUTHOR (149 words)

	CFD Review \| Density Functional Theory Simplifies Multiphase Simulation
		Traditional Eulerian multiphase simulation suffers from numerical problems at phase interfaces due to the large local density variation (eg.
		Density functional theory, however, describes the multicomponent multiphase mixture continuously without density jumps at interfacial surfaces.
		This is achieved by the introduction into the Helmholz energy, or into the entropy, square component density gradient terms.
	www.cfdreview.com /article.pl?sid=04/07/09/1524200&mode=nested (183 words)

	density functional theory beta version (Site not responding. Last check: )
		They should also be useful for developers, in allowing new students and postdocs to teach themselves basic DFT any time, on their own.
		Nobel lectures on DFT, including many useful references.
		{\em Density Functional Theory of Atoms and Molecules}, R.G. Parr and W. Yang (Oxford, New York, 1989).
	dft.rutgers.edu /kieron/beta (195 words)

	Amazon.ca: A Primer in Density Functional Theory: Books: Carlos Fiolhais,Fernando Nogueira,Miguel A.L. Marques (Site not responding. Last check: )
		Density functional theory (DFT) is by now a well-established method for tackling the quantum mechanics of many-body systems.
		Originally applied to compute properties of atoms and simple molecules, DFT has quickly become a work horse for more complex applications in the chemical and materials sciences.
		The present set of lectures, spanning the whole range from basic principles to relativistic and time-dependent extensions of the theory, is the ideal introduction for graduate students or nonspecialist researchers wishing to familiarize themselves with both the basic and most advanced techniques in this field.
	www.amazon.ca /Primer-Density-Functional-Theory/dp/3540030832 (408 words)

	Home Page of Density Functional Theory
		The first Hohenberg-Kohn theorem asserts that the density of any system determines all ground-state properties of the system, that is, E=E[n0], where n0 is the ground-state density of the system.
		The other advantage of DFT is that it provides some chemically important concepts, such as elctronegativity (chemical potential), hardness (softness), Fukui function, response function, etc..
		Although in many cases it is enough, it is not at all satisfactory as a well-established theory.
	www.unc.edu /~shubin/dft.html (331 words)

	An exchange energy density functional
		It is possible to obtain a simple closed-form local density expression for the exchange energy using the ideal electron gas.
		The Thomas-Fermi functional was one of the first functionals invented in the early days of density functional theory.
		Systematic improvements of the functional do somewhat better, however, it was not until the exact formulation of density functional theory by Hohenberg and Kohn that the true power of density functional theory could be realized.
	www.nyu.edu /classes/tuckerman/stat.mechII/lectures/lecture_14/node3.html (316 words)

	Density-functional theory (Site not responding. Last check: )
		Density-functional theory is a powerful modern framework for new developments in the accurate calculation of electronic structure.
		The generation of numerical basis functions that include the exact atomic solutions for a given exchange-correlation functional.
		Solution of the Poisson equation is very fast, does not depend on the number of basis functions (only the evaluation of the density on the numerical grid does) and easily made "linear-scaling" with either new "fast-multipole" methods or linear-scaling Ewald methods.
	www.chem.umn.edu /groups/york/dft.html (251 words)

Try your search on: Qwika (all wikis)