Related Experiment Video
Updated: Mar 29, 2026
13:56
Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
8.5K
An Assessment of the vdW-TS Method for Extended Systems.
W A Al-Saidi1,2, Vamsee K Voora1, Kenneth D Jordan1
1Department of Chemistry and Center for Molecular and Materials Simulations, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
Journal of Chemical Theory and Computation
|November 25, 2015
Summary
The Tkatchenko-Scheffler van der Waals (vdW-TS) method was implemented in DFT code to study dispersion-dominated materials. This research provides optimized structures and properties for layered materials, noble-gas solids, and molecular crystals.
Area of Science:
- Condensed matter physics
- Materials science
- Computational chemistry
Background:
- Accurate modeling of van der Waals (vdW) interactions is crucial for understanding the properties of many materials.
- Dispersion forces significantly influence the structure and energetics of layered materials, molecular crystals, and noble-gas solids.
- Previous methods often struggled to capture these interactions effectively.
Purpose of the Study:
- To implement the Tkatchenko-Scheffler (vdW-TS) method within a plane-wave Density Functional Theory (DFT) code.
- To characterize the structural and energetic properties of dispersion-dominated systems.
- To validate the vdW-TS method by comparing computational results with experimental data.
Main Methods:
- Implementation of the vdW-TS method in a plane-wave DFT framework.
- Full structural optimizations, including unit cell stress relaxation.
- Calculation of internal geometrical parameters, lattice constants, bulk moduli, and cohesive energies.
Main Results:
- The vdW-TS method was successfully integrated into the DFT code.
- Optimized structures and accurate physical properties were obtained for layered materials, noble-gas solids, and molecular crystals.
- Calculated properties show good agreement with available experimental results.
Conclusions:
- The implemented vdW-TS method provides a reliable approach for studying dispersion-dominated materials.
- This work validates the accuracy of the vdW-TS method for a range of condensed matter systems.
- The study offers valuable insights into the structural and energetic properties of these materials.
More Related Videos
Related Concept Videos
01:10Van der Waals Equation
6.9K
The ideal gas law is an approximation that works well at high temperatures and low pressures. The van der Waals equation of state (named after the Dutch physicist Johannes van der Waals, 1837−1923) improves it by considering two factors.
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
6.9K
01:26The Van der Waals Equation
143
The ideal gas law is based on two simplifying assumptions: first, that there are no intermolecular attractions between gas molecules, and second, that the volume occupied by the molecules themselves is negligible compared with the volume of the container. However, these assumptions don't hold up under all conditions - specifically, at high pressures and low temperatures, as gas tends to deviate from ideal gas behavior.The van der Waals equation is an enhanced version of the ideal gas law,...
143
01:24Van der Waals Interactions
73.2K
Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions between particles with permanent, partial, or temporary charges. The intermolecular forces between neutral atoms and molecules are ion–dipole, dipole–dipole, and dispersion forces, collectively known as van der Waals forces.
73.2K
04:01Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation
40.1K
Thus far, the ideal gas law, PV = nRT, has been applied to a variety of different types of problems, ranging from reaction stoichiometry and empirical and molecular formula problems to determining the density and molar mass of a gas. However, the behavior of a gas is often non-ideal, meaning that the observed relationships between its pressure, volume, and temperature are not accurately described by the gas laws.
40.1K
02:13Energy Diagrams, Transition States, and Intermediates
22.3K
Free-energy diagrams, or reaction coordinate diagrams, are graphs showing the energy changes that occur during a chemical reaction. The reaction coordinate represented on the horizontal axis shows how far the reaction has progressed structurally. Positions along the x-axis close to the reactants have structures resembling the reactants, while positions close to the products resemble the products. Peaks on the energy diagram represent stable structures with measurable lifetimes, while...
22.3K
02:26SN2 Reaction: Transition State
13.1K
An SN2 reaction of an alkyl halide is a single-step process in which bond formation between the nucleophile and the substrate and bond breaking between the substrate and the halide occurs simultaneously through a transition state without forming an intermediate.
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
13.1K