Quasiparticle calculation of the dielectric response of silicon and germanium

Levine, Zachary H.; Allan, Douglas C.

doi:10.1103/physrevb.43.4187

Cited by 220 publications

(131 citation statements)

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“…This discrepancy can be corrected semi-empirically by applying a self-energy correction, also referred to as a scissor correction, which consists of a rigid shift of the conduction bands with respect to the valence bands 20 . This procedure has been used successfully to reproduce the photoelasticity of Si 21 , GaAs 22 and quartz 19 .…”

Section: Computational Detailsmentioning

confidence: 99%

Photoelasticity of sodium silicate glass from first principles

2004

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Based on density-functional perturbation theory we have computed the photoelastic tensor of a model of sodium silicate glass of composition (Na2O)0.25(SiO2)0.75 (NS3). The model (containig 84 atoms) is obtained by quenching from the melt in combined classical and Car-Parrinello molecular dynamics simulations. The calculated photoelastic coefficients are in good agreement with experimental data. In particular, the calculation reproduces quantitatively the decrease of the photoelastic response induced by the insertion of Na, as measured experimentally. The extension to NS3 of a phenomenological model developed in a previous work for pure a-SiO2 indicates that the modulation upon strain of other structural parameters besides the SiOSi angles must be invoked to explain the change in the photoelstic response induced by Na.

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Section: Computational Detailsmentioning

confidence: 99%

Photoelasticity of sodium silicate glass from first principles

2004

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“…Similar shifts, though smaller in magnitude, have been obtained in the dielectric matrix methods. 7,8,16,28 Including the exchange-correlation contribution in the coupled response raises the value again, relative to the Coulomb-only value by 10%, to 10.9. We can conclude that both the Coulomb interaction and exchange-correlation effects contribute considerably to the dielectric response, and that they are in the order of about 10%-15%.…”

Section: Resultsmentioning

confidence: 93%

“…Amongst the exceptions the most prominent is the large deviation for the energy gap and the dielectric constant in semiconductors and insulators. The value for the dielectric constant obtained within the local density approximation ͑LDA͒ is usually much larger ͑more than 10%͒ 7,8 than the experimental data. A similar overestimation has been found for the static polarizabilities of atoms.…”

Section: Introductionmentioning

confidence: 77%

“…12,13 The error in the Kohn-Sham energy gap can be attributed to a discontinuity in the DFT exchange-correlation potential 14,15 and it is commonly believed that the gap has to be corrected by a rigid shift of the virtual states in order to get good results for the quasiparticle energies and dielectric constant. 8,[16][17][18] There is however no formal justification within DFT for this so-called scissors operator. 13 In some materials, one has to use a different shift in order to match the excitation spectrum than to get a correct dielectric constant.…”

Section: Introductionmentioning

confidence: 99%

“…7,8,16 This combination facilitates the description for the induced properties, like density and induced fields in Fourier space. 26,27 Self-consistency is achieved in a method which needs the construction of various response kernels as large matrix representations on this plane-wave basis, and for which one usually has to invert these matrices.…”

Section: Introductionmentioning

confidence: 99%

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Efficient real-space approach to time-dependent density functional theory for the dielectric response of nonmetallic crystals

Kootstra

Boeij

Snijders

2000

The Journal of Chemical Physics

100

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Efficient real-space approach to time-dependent density functional theory for the dielectric response of nonmetallic crystals Kootstra, F.; de Boeij, P. L.; Snijders, J. G. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Time-dependent density functional theory has been used to calculate the static and frequency-dependent dielectric function ⑀( ) of nonmetallic crystals. We show that a real-space description becomes feasible for crystals by using a combination of a lattice-periodic ͑microscopic͒ scalar potential with a uniform ͑macroscopic͒ electric field as perturbation in a periodic structure calculation. The induced density and microscopic potential can be obtained self-consistently for fixed macroscopic field by using linear response theory in which Coulomb interactions and exchange-correlation effects are included. We use an iterative scheme, in which density and potential are updated in every cycle. The explicit evaluation of Kohn-Sham response kernels is avoided and their singular behavior as function of the frequency is treated analytically. Coulomb integrals are evaluated efficiently using auxiliary fitfunctions and we apply a screening technique for the lattice sums. The dielectric function can then be obtained from the induced current. We obtained ⑀( ) for C, Si, and GaAs within the adiabatic local density approximation in good agreement with experiment. In particular in the low-frequency range no adjustment of the local density approximation ͑LDA͒ band gap seems to be necessary.

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Theoretical Basis for the Development of Borate Nonlinear Optical Crystals

Chen

Sasaki

et al. 2012

Nonlinear Optical Borate Crystals

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Today, we have confidence to say that the discovery of borate series NLO crystals is inseparable from the theoretical understanding of the relationship between the macroscopic NLO and LO properties of the NLO crystals and their microscopic structures. If we had not done a lot of calculations for SHG coefficients of the known NLO crystals and suggested the anionic group theory from the mid-1960s to the end of 1970s, it was nearly impossible to discover the borate NLO crystals in the 1980s. Therefore, this chapter describes the basic concepts and an approximation calculation method for the anionic group theory of NLO effect in crystals, and furthermore, use the model to elucidate the relationship between the macroscopic NLO and LO properties of NLO crystals and their microscopic structures, anionic group structures in particular. Moreover, we have also employed the first-principles method to study the NLO effects and elucidated their microscopic structural origins. On the basis of the theoretical understanding, the processes leading to the discovery of the borate series NLO crystals are further described.In Section 2.1, the basic concepts and calculation method of the anionic group theory of NLO effects in crystals are described with emphasis on the basic idea and the degree of approximation of the theory. In Section 2.2, several typical examples of the principal NLO crystals are given to explain that the major structural units of the NLO crystals to produce SHG effect on the crystals are certainly anionic groups and the contributions of cations in the crystals to the SHG effect can be ignored in the first approximation. In Section 2.3, a DV-SCM-X a localized cluster calculation method is employed to calculate the energy-level structure of the anionic groups in the NLO crystals. From the calculations one can understand the relationship between the energy-level structure of the anionic groups and absorption edge of the NLO crystals. The understanding is very helpful for the molecular engineering approach to search for UV and deep-UV NLO crystals. In Section 2.4, a first-principles calculation method with a plane wave pseudopotential (PWPP) total energy package is used to calculate the refractive indices, SHG coefficients of the NLO crystals, and then a realspace atom-cutting technique is employed to analyze the effect of cations on the SHG coefficients in the NLO crystals and determine the approximation degree of the anionic group theory. In Section 2.5, a computer-assisted molecular design system is introduced, in which the theoretical calculations and experimental methods are Nonlinear Optical Borate Crystals: Principles and Applications, First Edition.

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Quasiparticle calculation of the dielectric response of silicon and germanium

Cited by 220 publications

References 91 publications

Photoelasticity of sodium silicate glass from first principles

Photoelasticity of sodium silicate glass from first principles

Efficient real-space approach to time-dependent density functional theory for the dielectric response of nonmetallic crystals

Theoretical Basis for the Development of Borate Nonlinear Optical Crystals

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