Manipulation of lattice strain is emerging as a powerful means to modify the properties of low-dimensional materials. Most approaches rely on external forces to induce strain, and the role of interlayer van der Waals (vdW) coupling in generating strain profiles in homobilayer transition metal dichalcogenide (TMDC) films is rarely considered. Here, by applying atomic-resolution electron microsco...

Recently, the nonlocal van der Waals (vdW) density functionals [M. Dion, H. Rydberg, E. Schröder, D. C. Langreth, and B. I. Lundqvist, Phys. Rev. Lett. 92, 246401 (2004)] have attracted considerable attention due to their good performance for systems where weak interactions are important. Since the physics of dispersion is included in these functionals, they are usually more accurate and show l...

A recently developed ab initio van der Waals density functional (vdWDF) [1] includes long-range dispersion forces at an electronic level. It promises to extend large-scale electronic structure calculations to the realm of soft and sparse matter. Consequently, it has spurred many studies on supramolecular systems including molecular dimers, physisorption systems, and polymer bundles [2]. We inve...

Using differential quadrature method (DQM), this study investigated pull-in instability of beam-type nano-switches under the effects of small-scale and intermolecular forces including the van der Waals (vdW) and the Casimir forces. In these nano-switches, electrostatic forces served as the driving force, and von-Karman type nonlinear strain was used to examine nonlinear geometric effects. To de...

Recently, it was shown that when a single protuberance is introduced on an infinite flat conducting surface, anisotropic particle, kept constrained to move plane above the can feel not only lateral van der Waals (vdW) force leads protuberance, but, narrow enough, moves away from protuberance. Although this sign inversion in vdW found be related increasing curvature of role directly isolated eff...

First-principles calculations of phenol adsorbed on two different surfaces, graphite 0001 and -Al2O3 0001 , are performed with traditional semilocal density functional theory DFT and with a recently presented density functional vdW-DF that incorporates the dispersive van der Waals vdW interactions Phys. Rev. Lett. 92, 246401 2004 . The vdW-DF is of decisive importance for describing the vdW bon...

Two dimensional atomic crystals, like grapheme (G) and molybdenum disulfide (MoS2), exhibit great interest in electronic and optoelectronic applications. The excellent physical properties, such as transparency, semiconductivity, and flexibility, make them compatible with current organic electronics. Here, we review recent progress in the understanding of the interfaces of van der Waals (vdW) he...

Sparse matter is characterized by regions with low electron density and its understanding calls for methods to accurately calculate both the van der Waals vdW interactions and other bonding. Here we present a first-principles density-functional theory DFT study of a layered oxide V2O5 bulk structure which shows charge voids in between the layers and we highlight the role of the vdW forces in bu...

In applying the Poisson-Boltzmann (PB) equation for calculating the electrostatic free energies of solute molecules, an open question is how to specify the boundary between the low-dielectric solute and the high-dielectric solvent. Two common specifications of the dielectric boundary, as the molecular surface (MS) or the van der Waals (vdW) surface of the solute, give very different results for...

The evaluation of hydration free energies is a sensitive test to assess force fields used in atomistic simulations. We showed recently that the vibrational relaxation times, 1D- and 2D-infrared spectroscopies for CN(-) in water can be quantitatively described from molecular dynamics (MD) simulations with multipolar force fields and slightly enlarged van der Waals radii for the C- and N-atoms. T...