Dear Wajid,
Generally, the DFT calculations results for solid state systems predict fairly good and agree quite satisfactorily with the experimental data. Computational costs are relatively low compared to Hartree–Fock theory and its descendants based on the complex many-electron wave-function.
In general, density functional theory finds increasingly broad application in the chemical and material sciences for the interpretation and prediction of complex system behavior at an atomic scale. Specifically, DFT computational methods are applied for the study of systems to synthesis and processing parameters. In such systems, experimental studies are often encumbered by inconsistent results and non-equilibrium conditions. Examples of contemporary DFT applications include studying the effects of dopants on phase transformation behavior in oxides, magnetic behavior in dilute magnetic semiconductor materials and the study of magnetic and electronic behavior in ferroelectrics and dilute magnetic semiconductors.
On the other hand, the predecessor to DFT was the Thomas–Fermi model, which uses a statistical model to approximate the distribution of electrons in an atom. The Thomas–Fermi equation's accuracy is limited because the resulting kinetic energy functional is only approximate, and because the method does not attempt to represent the exchange energy of an atom as a conclusion of the Pauli principle. An exchange energy functional was added by Dirac in 1928. However, the Thomas–Fermi–Dirac theory remained rather inaccurate for most applications. The largest source of error was in the representation of the kinetic energy, followed by the errors in the exchange energy, and due to the complete neglect of electron correlation. Teller showed that Thomas–Fermi theory cannot describe molecular bonding. This can be overcome by improving the kinetic energy functional.
References:
Segall, M.D.; Lindan, P.J (2002). "First-principles simulation: ideas, illustrations and the CASTEP code". Journal of Physics: Condensed Matter 14 (11): 2717. Bibcode:2002JPCM...14.2717S. doi:10.1088/0953-8984/14/11/301.
"Ab initio study of phase stability in doped TiO2". Computational Mechanics 50 (2): 185–194. 2012. doi:10.1007/s00466-012-0728-4.
Parr & Yang 1989, p. 47
March, N. H. (1992). Electron Density Theory of Atoms and Molecules. Academic Press. p. 24. ISBN 0-12-470525-1.
Hoping this will be helpful,
Rafik
Dear Wajid,
Generally, the DFT calculations results for solid state systems predict fairly good and agree quite satisfactorily with the experimental data. Computational costs are relatively low compared to Hartree–Fock theory and its descendants based on the complex many-electron wave-function.
In general, density functional theory finds increasingly broad application in the chemical and material sciences for the interpretation and prediction of complex system behavior at an atomic scale. Specifically, DFT computational methods are applied for the study of systems to synthesis and processing parameters. In such systems, experimental studies are often encumbered by inconsistent results and non-equilibrium conditions. Examples of contemporary DFT applications include studying the effects of dopants on phase transformation behavior in oxides, magnetic behavior in dilute magnetic semiconductor materials and the study of magnetic and electronic behavior in ferroelectrics and dilute magnetic semiconductors.
On the other hand, the predecessor to DFT was the Thomas–Fermi model, which uses a statistical model to approximate the distribution of electrons in an atom. The Thomas–Fermi equation's accuracy is limited because the resulting kinetic energy functional is only approximate, and because the method does not attempt to represent the exchange energy of an atom as a conclusion of the Pauli principle. An exchange energy functional was added by Dirac in 1928. However, the Thomas–Fermi–Dirac theory remained rather inaccurate for most applications. The largest source of error was in the representation of the kinetic energy, followed by the errors in the exchange energy, and due to the complete neglect of electron correlation. Teller showed that Thomas–Fermi theory cannot describe molecular bonding. This can be overcome by improving the kinetic energy functional.
References:
Segall, M.D.; Lindan, P.J (2002). "First-principles simulation: ideas, illustrations and the CASTEP code". Journal of Physics: Condensed Matter 14 (11): 2717. Bibcode:2002JPCM...14.2717S. doi:10.1088/0953-8984/14/11/301.
"Ab initio study of phase stability in doped TiO2". Computational Mechanics 50 (2): 185–194. 2012. doi:10.1007/s00466-012-0728-4.
Parr & Yang 1989, p. 47
March, N. H. (1992). Electron Density Theory of Atoms and Molecules. Academic Press. p. 24. ISBN 0-12-470525-1.
Hoping this will be helpful,
Rafik
DFT is a computational quantum mechanical modeling method used in Physics, Chemistry and Material Science to investigate electronic structure of many electron atoms and molecules, principally in their respective ground states.
All most all characteristics- be it any spectral parameter of IR/Raman/ NMR/ESR/ NQR/ CD/ORD/ Mossbauer , magnetic, electronic and geometrical structures of a system are all the functions of only one parameter- SPATIALLY DEPENDENT ELECTRON DENSITY- meaning, thererby,that these parameters are THE FUNCTIONS OF ANOTHER FUNCTION(ELECTRON DENSITY) and hence the name Density functional theory( note the word functional)- the function of another parameter- the electron density.
[2] Then comes it’s the simplest way of its implementation. You can implement DFT through certain soft wares( Gaussian o9 or ADF) by installing them on Window XP-7,8,10. and you get required results by filling in certain codes or commands.
[3]You don’t need to purchase costly diagnostic elements- only a definite software ( of your choice) will be available either free or on yearly license.
As regards to its advantage over Statistical Approximations in Solid State Physics (T-F model)and Traditional Hartree- Fock (HF) and post-HF approaches:
(a) You apply different concepts to determine different parameters in different atoms
(b) There would be huge discrepancies in the actual energies( kinetic/ exchange)
(c) And above all, it cannot accurately describe the molecular bonding.
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