Related Experiment Video
Updated: May 26, 2026
13:56
Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
Reliability of hybrid functionals in predicting band gaps
Manish Jain1, James R Chelikowsky, Steven G Louie
1Department of Physics, University of California, Berkeley, 94720, USA.
Physical Review Letters
|December 21, 2011
Summary
Hybrid functionals often fail to accurately predict electronic band gaps for materials, especially in different structural configurations like surfaces and nanostructures. This research highlights their limitations for reliable electronic structure calculations.
Area of Science:
- Computational Materials Science
- Condensed Matter Physics
- Quantum Chemistry
Background:
- Hybrid functionals are widely used in computational chemistry and physics to approximate electronic structure.
- Accurate prediction of electronic band gaps is crucial for understanding and designing materials.
- Previous studies have shown varying success rates for hybrid functionals in different material systems.
Purpose of the Study:
- To evaluate the reliability of orbital energies from hybrid functionals for predicting electronic band gaps.
- To assess the accuracy of these functionals across diverse structural configurations, including bulk, surfaces, and nanostructures.
- To identify limitations of commonly used hybrid functionals for specific material properties.
Main Methods:
- Calculations of electronic band gaps using a range of established hybrid functionals.
- Comparison of calculated band gaps with experimental or high-level theoretical data for various systems.
- Analysis of the performance of functionals for bulk materials, semiconductor surfaces (e.g., Si(111)-(2 × 1)), and graphene nanoribbons.
Main Results:
- Orbital energies from hybrid functionals do not consistently yield reliable band gaps.
- Functionals accurate for bulk band gaps often fail for different structural configurations like surfaces and nanostructures.
- Specific examples include inadequate description of the Si(111)-(2 × 1) surface-state gap and discrepancies in quasiparticle vs. optical gaps for graphene nanoribbons.
Conclusions:
- Existing hybrid functionals exhibit significant limitations in accurately predicting electronic band gaps across various material structures.
- Careful selection and validation of hybrid functionals are necessary for reliable electronic structure calculations, particularly for surface and nanoscale systems.
- Strong variations among different hybrid functionals necessitate further development for improved predictive power in diverse material contexts.
More Related Videos
08:04Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
12:08Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes
Published on: June 24, 2022
Related Concept Videos
01:21IR Absorption Frequency: Hybridization
Hydrocarbons such as alkanes, alkenes, and alkynes show characteristic C–H stretching absorption bands. These IR stretching frequencies depend on the hybridization of the involved carbon atom and can be explained in terms of the s character of each hybridized atomic orbital.
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...
03:24Hybridization of Atomic Orbitals I
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
02:38Valence Bond Theory and Hybridized Orbitals
According to valence bond theory, a covalent bond results when: (1) an orbital on one atom overlaps an orbital on a second atom, and (2) the single electrons in each orbital combine to form an electron pair. The strength of a covalent bond depends on the extent of overlap of the orbitals involved. Maximum overlap is possible when the orbitals overlap on a direct line between the two nuclei.
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
02:35Band Theory
When two or more atoms come together to form a molecule, their atomic orbitals combine and molecular orbitals of distinct energies result. In a solid, there are a large number of atoms, and therefore a large number of atomic orbitals that may be combined into molecular orbitals. These groups of molecular orbitals are so closely placed together to form continuous regions of energies, known as the bands.
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
03:35Hybridization of Atomic Orbitals II
sp3d and sp3d 2 Hybridization
01:01Energy Bands in Solids
Isolated atoms have discrete energy levels that are well described by the Bohr model. And, it quantifies the energy of an electron in a hydrogen atom as En. Higher quantum numbers 'n' yield less negative, closer electron energy levels.
Band Formation:
When atoms are brought close together, as in a solid, these discrete energy levels begin to split due to the overlap of electron orbitals from adjacent atoms. This split occurs because of the Pauli exclusion principle, which states that no two...
Band Formation:
When atoms are brought close together, as in a solid, these discrete energy levels begin to split due to the overlap of electron orbitals from adjacent atoms. This split occurs because of the Pauli exclusion principle, which states that no two...