In atom optics a material structure is commonly regarded as an amplitude mask for atom waves. However, atomic diffraction patterns formed using material gratings indicate that material structures also operate as phase masks. In this study a well collimated beam of sodium atoms is used to illuminate a silicon nitride grating with a period of 100 nm. During passage through the grating slots atoms...

The exploration of emerging materials physics and prospective applications of two-dimensional materials greatly relies on the growth control of their thickness, phases, morphologies, and film−substrate interactions. Though substantial progress has been made for the development of twodimensional films from conventional layered bulky materials, particular challenges remain for obtaining ultrathin...

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...

We report a van der Waals heterostructure formed by monolayers of MoS2 and ReS2 with a type-I band alignment. First-principle calculations show that in this heterostructure, both the conduction band minimum and the valence band maximum are located in the ReS2 layer. This configuration is different from previously accomplished type-II van der Waals heterostructures where electrons and holes resi...

In 1873, van der Waals proposed a simple equation of state that qualitatively described the phase behavior of fluids. Since then, the principles behind the van der Waals equation have been used and refined countless times in the quest for an accurate equation of state. Despite the enormous amount of work reported, the goal of a simple and accurate equation of state for even relatively simple sy...

For geometric and topological analysis and for understanding the nonbond interactions between atoms a protein is modeled as a set of spheres in R, each sphere corresponding to one atom of the protein. This model, known as the space-filling diagram, assumes that the exact position of each atom is known. We thus represent a protein P as a set {B1, . . . , Bn} of balls in R. Let zi (resp. ri) deno...

Selected allotropes of phosphorus are investigated by different levels of density functional theory (DFT) calculations to evaluate the relative stability orders with a special focus on the role of van der Waals interactions. Phosphorus is an excellent reference system with a large number of allotropes. Starting from low-dimensional molecular (0D, white P) and polymer structures (1D, P nanorods)...

The samples of DaGang atmospheric residue (DG-AR), Middle East atmospheric residue (ME-AR), TaHe atmospheric residue (TH-AR), and their thermal reaction samples were chosen for study. All the samples were fractioned into six components separately, including saturates plus light aromatics, heavy aromatics, light resins, middle resins, heavy resins, and asphaltenes. The dielectric permittivity of...

Freon-TF is no better a cleaning fluid than deionized water for removing either organic (polystyrene latex spheres) or inorganic (glass beads) particles from silicon wafer surfaces, as shown by comparative measurements of cleaning efficiencies in both an ultrasonic bath and a hydrodynamic cleaning apparatus. A primary reason for this lackluster performance is the higher van der Waals’ forces of...