An atomic version of the Millikan oil drop experiment is performed computationally. It is shown that for planar molecules, the atomic version of the Millikan experiment can be used to define an atomic partial charge that is free from charge flow contributions. We refer to this charge as the Millikan-Thomson (MT) charge. Since the MT charge is directly proportional to the atomic forces under a u...

A model of the solid state of formamide is constructed by optimizing a central molecule in an elect rostat ic field of the proper symmetry. Attent ion is paid to the way the electrostat ic charges are obtained. Point charges obtained from a Mulliken population analysis yield a final set of atomic charges in the central molecule that agree reasonably well with those obtained experimentally af te...

Molecular dynamics simulations of dipalmitoylphosphatidylcholine (DPPC) lipid bilayers using the CHARMM27 force field in the tensionless isothermal-isobaric (NPT) ensemble give highly ordered, gel-like bilayers with an area per lipid of approximately 48 A(2). To obtain fluid (L(alpha)) phase properties of DPPC bilayers represented by the CHARMM energy function in this ensemble, we reparameteriz...

Experimental measurements of edge-to-face aromatic interactions have been used to test a series of molecular mechanics force fields. The experimental data were determined for a range of differently substituted aromatic rings using chemical double mutant cycles on hydrogen-bonded zipper complexes. These complexes were truncated for the purposes of the molecular mechanics calculations so that pro...

We examine the possibility that gauge field configurations on stacks of parallel Dp-branes support topological solitons. We give an exhaustive list of possible soliton charges for p ≤ 6. We also discuss how configurations carrying the soliton charges can be constructed from intersecting branes.

By placing theories with Yangian charges on the lattice in the analogue of the St Petersburg school’s approach to the sine-Gordon system, we exhibit the Yangian structure of the auxiliary algebra, and explain how the two Yangians are related.

We study interatomic forces in a fluid consisting of a mixture of free charges and neutral atoms in the framework of the quantum many-body problem at nonzero temperature and nonzero density. Of central interest is the interplay between van der Waals forces and screening effects due to free charges. The analysis is carried out in a partially recombined hydrogen plasma in the Saha regime. The eff...

Coupled coaxially stacked toroidal condensates with persistent currents suggest an appealing physical platform for the investigation of various phenomena related to interacting superflows from Josephson effects in regime weak interactions quantum Kelvin-Helmholtz instability merging rings. We experimentally accessible methods prepare states different topological charges two coupled coaxial ring...

The electronic and structural properties of retinal and four analogs were studied using semiempirical, ab initio Hartree-Fock, and density functional theory methods with the aim to evaluate the effects caused by some structural modifications in the ring bound to the polyenic chain and compared with the all-E-trans-retinal molecule. Therefore, some properties such as bond lengths, bond angles, a...

Effective nuclear charges of the main group elements from the second up to the fifth row have been developed for the one-electron part of the spin-orbit (SO) coupling Hamiltonian. These parameters, suitable to be used for SO calculations of large molecular systems, provide a useful and remarkably good approximation to the full SO Hamiltonian. We have derived atomic effective nuclear charges by ...