The (4, +) energy surface of blocked alanine (N-acetyl-N'-methyl alanineamide) was calculated at the Hartree-Fock (HF)/6-31G* level using ab initio molecular orbital theory. A collection of six electrostatic models was constructed, and the term electrostatic model was used to refer to (1) a set of atomic charge densities, each unable to deform with conformation; and (2) a rule for estimating th...

Measurements of the Casimir force require the elimination of the electrostatic force between the surfaces. However, due to electrostatic patch potentials, the voltage required to minimize the total force may not be sufficient to completely nullify the electrostatic interaction. Thus, these surface potential variations cause an additional force, which can obscure the Casimir force signal. In thi...

Two-dimensional dispersions of colloidal particles with a range of surface chemistries and electrostatic potentials are characterized under a series of solution ionic strengths. A combination of optical imaging techniques are employed to monitor both the colloid structure and the electrostatic surface potential of individual particles in situ. We find that like-charge multiparticle interactions...

The molecular electrostatic potential and steric accessibility of A-DNA are computed for base sequences (dG.dC)n and (dA.dT)n. An interpretation of the results in terms of the structure of A-DNA is provided and differences with respect to other forms of DNA, namely B-DNA and Z-DNA, are discussed.

A liquid is composed of an ensemble of molecules that populate a large number of different states, so calculation of the solvation energy of a molecule in solution requires a method for summing the interactions with the environment over all of these states. The surface site interaction model for the properties of liquids at equilibrium (SSIMPLE) simplifies the surface of a molecule to a discret...

We performed equilibrium and nonequilibrium molecular dynamics simulation to study electro-osmotic flows inside charged nanochannels with different types of surface roughness. We modeled surface roughness as a sequence of two-dimensional subnanoscale grooves and ridges (step function-type roughness) along the flow direction. The amplitude, spatial period, and symmetry of surface roughness were ...