Band structures for excited state spectroscopies

R.W. Godby; R.J. Needs

doi:10.1088/0031-8949/1990/T31/031

Band structures for excited state spectroscopies

R.W. Godby, R.J. Needs

Physics

Research output: Contribution to journal › Article › peer-review

Abstract

By calculating an exchange-correlation potential from the self-energy operator, we show that interpretation of the one-electron band structure appearing in density-functional theory (DFT) calculations as quasiparticle energies is seriously invalid. For example, the well-known error in the minimum band gap of semiconductors and insulators is not caused by the use of the local density approximation (LDA), but is inherent to DFT. Furthermore, the metal-insulator transition undergone when a semiconductor is compressed is not described correctly within DFT, showing that the DFT Fermi surface is not necessarily that of the real system. However, excited state properties can be calculated correctly, by using computational many-body theory. The GW approximation for the self-energy operator gives quasiparticle energies in excellent agreement with experiment. It may also be used to obtain the one-particle Green's function, from which other properties of the system may be found.

Original language	English
Pages (from-to)	227-231
Number of pages	4
Journal	Physica Scripta
Volume	T31
DOIs	https://doi.org/10.1088/0031-8949/1990/T31/031
Publication status	Published - 1990

Bibliographical note

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10.1088/0031-8949/1990/T31/031

Cite this

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title = "Band structures for excited state spectroscopies",

abstract = "By calculating an exchange-correlation potential from the self-energy operator, we show that interpretation of the one-electron band structure appearing in density-functional theory (DFT) calculations as quasiparticle energies is seriously invalid. For example, the well-known error in the minimum band gap of semiconductors and insulators is not caused by the use of the local density approximation (LDA), but is inherent to DFT. Furthermore, the metal-insulator transition undergone when a semiconductor is compressed is not described correctly within DFT, showing that the DFT Fermi surface is not necessarily that of the real system. However, excited state properties can be calculated correctly, by using computational many-body theory. The GW approximation for the self-energy operator gives quasiparticle energies in excellent agreement with experiment. It may also be used to obtain the one-particle Green's function, from which other properties of the system may be found.",

author = "R.W. Godby and R.J. Needs",

note = "{\textcopyright} 1990 Institute of Physics.",

year = "1990",

doi = "10.1088/0031-8949/1990/T31/031",

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TY - JOUR

T1 - Band structures for excited state spectroscopies

AU - Godby, R.W.

AU - Needs, R.J.

PY - 1990

Y1 - 1990

N2 - By calculating an exchange-correlation potential from the self-energy operator, we show that interpretation of the one-electron band structure appearing in density-functional theory (DFT) calculations as quasiparticle energies is seriously invalid. For example, the well-known error in the minimum band gap of semiconductors and insulators is not caused by the use of the local density approximation (LDA), but is inherent to DFT. Furthermore, the metal-insulator transition undergone when a semiconductor is compressed is not described correctly within DFT, showing that the DFT Fermi surface is not necessarily that of the real system. However, excited state properties can be calculated correctly, by using computational many-body theory. The GW approximation for the self-energy operator gives quasiparticle energies in excellent agreement with experiment. It may also be used to obtain the one-particle Green's function, from which other properties of the system may be found.

AB - By calculating an exchange-correlation potential from the self-energy operator, we show that interpretation of the one-electron band structure appearing in density-functional theory (DFT) calculations as quasiparticle energies is seriously invalid. For example, the well-known error in the minimum band gap of semiconductors and insulators is not caused by the use of the local density approximation (LDA), but is inherent to DFT. Furthermore, the metal-insulator transition undergone when a semiconductor is compressed is not described correctly within DFT, showing that the DFT Fermi surface is not necessarily that of the real system. However, excited state properties can be calculated correctly, by using computational many-body theory. The GW approximation for the self-energy operator gives quasiparticle energies in excellent agreement with experiment. It may also be used to obtain the one-particle Green's function, from which other properties of the system may be found.

U2 - 10.1088/0031-8949/1990/T31/031

DO - 10.1088/0031-8949/1990/T31/031

M3 - Article

SN - 0031-8949

VL - T31

SP - 227

EP - 231

JO - Physica Scripta

JF - Physica Scripta

ER -