Individual phospholipid vesicles, 1 to 5 micrometers in diameter, containing a single reagent or complete reaction system, were immobilized with an infrared laser optical trap by adhesion modified borosilicate glass surfaces. Chemical transformations initiated either electroporation electrofusion, each case through application of short (10-microsecond), intense (20 50 kilovolts per centimeter) electric pulse delivered across ultramicroelectrodes. Product formation was monitored far-field...

This article is devoted to further development of the generalized van der Waals theory and its application non-uniform hard sphere fluids. A coarse-graining assumption included in original derivation replaced by a weaker recognizing non-zero range core interactions. The new fine-grained thus contains non-local entropy functional allows fluid structure on length scale shorter than diameter be resolved. Moreover, it simplified representation mechanism leading due essentially geometrical...

Experimental interest in the possible curvature dependence of particle charging electrolyte solutions is subjected to theoretical analysis. The corrected Debye−Hückel theory surface complexation (CDH-SC) and Monte Carlo (MC) simulation are applied investigate metal oxide nanoparticles on their size. Surface charge density versus pH curves for spherical size range 1−100 nm calculated at various concentrations a background electrolyte. nanoparticle found be highly size-dependent. As diameter...

A general and efficient microcanonical sampling (EMS) procedure based on that of Severin et al. [Chem. Phys. Lett. 57, 117 (1978)] is outlined. The relevant statistical weights are derived. EMS method can be used for the generation initial states trajectories or directly in calculation averages rate constants. validity usefulness demonstrated applications to 1D linear chains 3D molecules such as H2O, SiH2, Si2H6.

Projection operator techniques are used to separate the complete Hilbert space of a molecular system into parts corresponding bound and continuum states. The equation motion amplitude associated with an initial excitation molecule is then formulated; this contains memory effects. Although formally exact, its utility lies in approximations suggested by structure. Drawing on recent studies intramolecular relaxation, Markovian approximation formulated properties model so defined investigated...

In this second article on quantum ergodic properties of simple anharmonic molecular models, we present further numerical calculations for the Barbanis and Henon-Heiles models. For cases studied herein, density energy eigenstates is larger by about a factor five than that used earlier. We show character low lying states model Hamiltonians dominated λ-independent effects which can be obtained order degenerate perturbation theory. Nondegenerate modifications above systems are again found to...

Expressions for the molecular momentum density of states as a function spatial configuration in an angular resolved microcanonical ensemble are derived. These expressions then used to formulate efficient sampling scheme generation configurations or full phase space vectors where both energy and predetermined. Applications simple diatomic (OH) triatomic (H2O) models presented.

In the Poisson–Boltzmann theory of macroion screening in electrolyte solutions chief simplifying assumption is neglect correlations within ionic atmosphere. Using a generalized van der Waals density functional analysis incorporating ion–ion correlation local approximation we obtain simple corrected theory. For point charges salt free case, this leads to asymptotic instability (a ‘‘structuring catastrophe’’) though correction well behaved low orders perturbation Results zeroth order and field...

A generalized van der Waals theory is derived on the basis of simple physical and mathematical arguments. The derivation results in a free- energy functional wherein independent variable coarse-grained particle density. It assumed that well defined density dominates free this to be obtained by minimizing functional. variational so can applied non-uniform fluids. In present work possibility stable structure neglected uniform then produces an equation state identical form proposed originally...

An extensive series of Monte Carlo (MC) simulations were performed in order to explore the validity simple primitive models electrolyte solutions and particular effect ion size asymmetry on bulk thermodynamic properties real salt solutions. Ionic activity osmotic coefficients calculated for 1:1, 2:1, 3:1 electrolytes by using unrestricted model (UPM); i.e., ions are considered as charged hard spheres different sizes dissolved a dielectric continuum. Mean ionic MC fitted simultaneously...

A long-held view of the origin covalent binding is based on notion that electrostatic forces determine stability a system charged particles and that, therefore, potential energy changes drive stabilization molecules. key argument advanced for this conjecture rigorous validity virial theorem. Rigorous in-depth analyses have however shown lowering bonding due to wave mechanical electrons lower their kinetic through expansion. Since theorem applies only systems with Coulombic interaction...

A recently developed free energy density functional theory (GvdW theory) is here applied to adsorption of inert gases at a flat wall. This application illustrates the need for fine-grained version wherein entropy nonlocal. Calculation profiles argon adsorbed on an idealized carbon dioxide surface and krypton graphite indicate that GvdW somewhat underestimates amount nonuniform structure. Nevertheless, qualitatively correct quantitatively useful description obtained.

As a first step in the computational prediction of drug solubility free energy hydration, DeltaG*(vw) TIP4P water has been computed for data set 48 molecules using perturbation method and optimized potential liquid simulations all-atom force field. The were performed two steps, where Coulomb then Lennard-Jones interactions between solute scaled down from full to zero strength provide physical understanding simpler predictive models. results have interpreted theory assuming = A(MS)gamma +...

A model for solvation forces between two solute particles in a colloidal suspension is solved within the framework of generalized van der Waals (GvdW) fluids. The results this approximation are compared to machine simulations subcritical solvent. Density profiles, adsorption excess, and force interaction studied. Particular attention paid phenomenon liquid film formation as function interparticle distance. Theory simulation found be good overall agreement.

This work addresses the continuing disagreement between two prevalent schools of thought concerning mechanism covalent bonding. According to Hellmann, Ruedenberg, and Kutzelnigg, a lowering kinetic energy associated with electron delocalization is key stabilization mechanism. The opposing view Slater, Feynman, Bader has maintained that source electrostatic potential due density redistribution binding regions nuclei. Despite large body accurate quantum chemical on range molecules, debate...

The solubility of drugs in water is investigated a series papers. In this work, we address the process bringing drug molecule from vapor into pure amorphous phase. This step enables us to actually calculate water. our general approach, we, on one hand, perform rigorous free energy simulations using combination perturbation and thermodynamic integration methods. On other develop an approximate theory containing parameters that are easily accessible conventional Monte Carlo simulations,...