An efficient method is developed for the microscopic description of the frequency-dependent polarizability of finite-gap molecules and solids. This is achieved by combining the Tkatchenko-Scheffler van der Waals (vdW) method [Phys. Rev. Lett. 102, 073005 (2009)] with the self-consistent screening equation of classical electrodynamics. This leads to a seamless description of polarization and dep...

We study the role of electronic structure (band gaps) and long-range van der Waals (vdW) interactions on the stability and mobility of point defects in silicon and heavier semiconductors. Density functional theory calculations with hybrid functionals that contain part of the Hartree-Fock exchange energy are essential to achieve a reasonable description of defect electronic levels, leading to ac...

Measurement or estimation of leaf area is essential for understanding crop responses to experimental treatments. The objective of this study was to develop regression models for estimating leaf area of field-grown cotton (Gossypium hirsutum L.) from measurements of leaf dry weight (LDW), vegetative components (stems and leaves) dry weight (VDW) and plant height (PH). Three cotton cultivars (Del...

The drive towards nanoscale assembly necessitates an accurate understanding of all the fundamental forces present in a given system to ensure the greatest chance of success. The van der Waals London dispersion (vdW-Ld) interaction is the universal, long range, interaction that is present in all materials systems. However, scientists and engineers often either ignore or crudely approximate the v...

The importance of accurately treating van der Waals interactions between the quantum mechanical (QM) and molecular mechanical (MM) atoms in hybrid QM/MM simulations has been investigated systematically. First, a set of van der Waals (vdW) parameters was optimized for an approximate density functional method, the self-consistent charge-tight binding density functional (SCC-DFTB) approach, based ...

The influence of a simple semiempirical van der Waals vdW correction on the description of dispersive, covalent, and ionic bonds within density functional theory is studied. The correction is based on the asymptotic London form of dispersive forces and a damping function for each pair of atoms. It thus depends solely on the properties of the two atoms irrespective of their environment and is nu...

Folding and unfolding processes are important for the functional capability of polypeptides and proteins. In contrast with a physiological environment (solvated or condensed phases), an in vacuo study provides well-defined "clean room" conditions to analyze the intramolecular interactions that largely control the structure, stability, and folding or unfolding dynamics. Here we show that a prope...

van der Waals (vdW) dispersion interactions are a key ingredient in the structure, stability, and response properties of many molecular materials and essential for us to be able to understand and design novel intricate molecular systems. Pairwise-additive models of vdW interactions are ubiquitous, but neglect their true quantum-mechanical many-body nature. In this perspective we focus on recent...

Van der Waals (vdW) layered crystals and heterostructures have attracted substantial interest for potential applications in a wide range of emerging technologies. An important, but often overlooked, consideration in the development of implementable devices is phonon transport through the structure interfaces. Here we report on the interface properties of exfoliated InSe on a sapphire substrate....