Band structures and charge densities of KCl, NaF, and LiF obtained by the intersecting-spheres model

Antoci, S.; Mihich, L.

doi:10.1103/physrevb.21.799

Cited by 14 publications

(11 citation statements)

References 19 publications

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“…However the influence of electronegativity is considerably smaller than the influence of p-d hybridization, as explained by Jaffe et al, [56,57]. The degree of pd hybridization between the Cu-d states and anion-p states determines the valence band energies and band offsets [14][15][16] in which a good mixing of pd orbitals ensures more Cu d states being located at the valence band edge [56]. This mixing is mainly controlled by the energy levels of the atomic orbitals of the constitutes, and changing bond length directly affect this degree of hybridization.…”

Section: Density Of Statesmentioning

confidence: 96%

“…But it is observed that mBJ+U potential causes a rigid displacement of the conduction bands towards higher energies with respect to the top of the valence band with small differences in the dispersion at same regions of the Brillouin zone. Thus reproducing, in general is the characteristic behavior of the bands for semiconductors according to experiment [14][15][16] as the WIEN2k code used to. For all the three schemes the valence band (VB) has two main sub-bands.…”

Section: Electronic Properties: Band Structurementioning

confidence: 99%

“…This is because of the fact that GGA does not consider the existence of derivative discontinuity of energy with respect to the number of electrons. For a group of compounds which has similar generic nature, such as ZnX, CuGeX 2 and Cu 2 ZnGeX 4 , this derivative discontinuity term is almost the same [12][13][14]. Therefore, the band gap discrepancy due to the usage of GGA compared to experimental band gap values are expected to be similar for the group of similar compounds [14].…”

Section: Introductionmentioning

confidence: 99%

“…For a group of compounds which has similar generic nature, such as ZnX, CuGeX 2 and Cu 2 ZnGeX 4 , this derivative discontinuity term is almost the same [12][13][14]. Therefore, the band gap discrepancy due to the usage of GGA compared to experimental band gap values are expected to be similar for the group of similar compounds [14]. But TB-mBJ is a direct alternate for GW or hybrid functional which yields comparable accuracy with experimental values [17].…”

Section: Introductionmentioning

confidence: 99%

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Band Gap Engineering of Cu2-II-IV-VI4 Quaternary Semiconductors Using PBE-GGA, TB-mBJ and mBJ+U Potentials

Bhavani¹,

John²

2019

IJSRPAS

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The structural and electronic properties of Cu 2 ZnGeX 4 (X = S, Se and Te) with a tetrahedral coordinated stannite structure have been investigated using first-principles calculations. The optimized lattice constants, anion displacement u, tetragonal distortion parameter η, band gap, density of states and bulk modulus values are reported. The modified Becke-Johnson exchange potential (TB-mBJ), is used to calculate the electronic properties of Cu based quaternary semiconductors Cu 2 ZnGeX 4 (X = S, Se and Te) and thus the results for the band gap and other electronic properties such as Total Density of States (TDOS) and Partial Density of States (PDOS) are analyzed in detail. Also the results obtained using TB-mBJ potential are compared with the standard local density and generalized gradient approximation (GGA). Even though the comparison of results shows that the results obtained by TB-mBJ are still underestimating the experimental results. This explains the inadequacy of mBJ potential for semiconductors with strongly delocalized d electrons. Thus in this paper an on-site Coulomb U is incorporated within mBJ potential (mBJ + U) which leads to a better description of the pd hybridization and therefore the band gap which is very much comparable with the experimental results.

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Section: Density Of Statesmentioning

confidence: 96%

Section: Electronic Properties: Band Structurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Band Gap Engineering of Cu2-II-IV-VI4 Quaternary Semiconductors Using PBE-GGA, TB-mBJ and mBJ+U Potentials

Bhavani¹,

John²

2019

IJSRPAS

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“…1, we compare the band structure for Si, Ge, GaAs and LiF calculated with the LDA and with the mBJLDA potential. As a general result, this potential causes a rigid displacement of the conduction bands toward higher energies with respect to the top of the valence band with small differences in the dispersion at some regions of the Brillouin zone but reproducing, in general, the characteristic behavior of the bands for each semiconductor according to experiment [23,24,32,33] as the Wien2k code used to. If we look at the resulting band structures in more detail, we see that a rigid displacement of only the conduction bands as to reproduce the mBJLDA predicted gap value will cause some differences in the upper conduction bands although the ones just above the upper gap edge will match quite well with the calculation using the mBJLDA potential.…”

Section: Band Structure Calculationsmentioning

confidence: 99%

Performance of the modified Becke-Johnson potential

Camargo-Martinez,

Baquero

2012

Preprint

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Very recently, in the 2011 version of the Wien2K code, the long standing shortcome of the codes based on Density Functional Theory, namely, its impossibility to account for the experimental band gap value of semiconductors, was overcome. The novelty is the introduction of a new exchange and correlation potential, the modified Becke-Johnson potential (mBJLDA). In this paper, we report our detailed analysis of this recent work. We calculated using this code, the band structure of forty one semiconductors and found an important improvement in the overall agreement with experiment as Tran and Blaha [Phys. Rev. Lett. 102, 226401 (2009)] did before for a more reduced set of semiconductors. We find, nevertheless, within this enhanced set, that the deviation from the experimental gap value can reach even much more than 20%, in some cases. Furthermore, since there is no exchange and correlation energy term from which the mBJLDA potential can be deduced, a direct optimization procedure to get the lattice parameter in a consistent way is not possible as in the usual theory. These authors suggest that a LDA or a GGA optimization procedure is used previous to a band structure calculation and the resulting lattice parameter introduced into the 2011 code. This choice is important since small percentage differences in the lattice parameter can give rise to quite higher percentage deviations from experiment in the predicted band gap value. We found that by using the average of the two lattice parameters (LDA and GGA) a better agreement with the band gap experimental value is systematically obtained. As a rule, the LDA optimization underestimates the lattice parameter while the GGA one overestimates it. Also we found that using the experimental lattice parameter instead, surprisingly high deviations of the predicted band gap value from experiment, occur. This is an odd result since, in general, the quality of the LDA and GGA obtained lattice parameters are judged to be as good as their proximity to the experimental lattice parameter value. This judgment implies the idea that the best result for the predicted band gap value is obtained when the closest-to-experiment lattice parameter is used. On the other hand, the band structure calculated with the mBJLDA potential seems, at first sight, a simple rigid displacement of the conduction bands towards higher energies. A closer look reveals that, in some cases, important differences occur that might not be negligible in certain systems containing a semiconductor as it might happen at interfaces. So, in some systems containing a semiconductor, neither the direct use of the Wien2k previous version nor its use with a rigid displacement of the conduction bands added so as to reproduce the band gap value, are totally reliable. The overall implementation of the calculation of the band structure of semiconductors with the Wien2k code using this new potential is quite empirical although it mimics well the results obtained by other methods as the GW approximation which give better results and a...

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Electronic Structure and Properties of Cubic Boron Nitride

Prasad

Dubey

1984

Physica Status Solidi (b)

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The electronic structure of cubic boron nitride without and with fractional ionicity is calculated by the application of the composite wave variational version of the APW method. The main calculations are performed a t the high symmetry points l?, X, and L, and the rest of the band structure is obtained by the tight-binding interpolation scheme of Slater and Koster. The density of states, imaginary part of the dielectric constant, and the effect of pressure on them are calculated and compared with available experimental and theoretical data. Die elektronische Struktur von kubischem Bornitrid mit und ohne Ionizitatsanteil werden durch Anwendung der Variationsversion zusammengesetzter Wellen der APW-Methode berechnet. DieHauptberechnung wird an den hochsymmetrischen Punkten r, X und L durchgefuhrt, und der Rest der Bandstruktur wird mit dem "tight-binding'' Interpolationsschema von Slater und Koster erhalten. Die Zustandsdichte, der Imaginarteil der Dielektrizitatskonstante und ihre Druckabhangigkeiten werden berechnet und mit verfiigbaren experimentellen und theoretischen Werten verglichen.

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Band structures and charge densities of KCl, NaF, and LiF obtained by the intersecting-spheres model

Cited by 14 publications

References 19 publications

Band Gap Engineering of Cu2-II-IV-VI4 Quaternary Semiconductors Using PBE-GGA, TB-mBJ and mBJ+U Potentials

Band Gap Engineering of Cu2-II-IV-VI4 Quaternary Semiconductors Using PBE-GGA, TB-mBJ and mBJ+U Potentials

Performance of the modified Becke-Johnson potential

Electronic Structure and Properties of Cubic Boron Nitride

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