Molecular dynamics computer simulations were performed for (H2O)n ~n512, 16, and 20! followed by systematic quenching under a polarizable and a nonpolarizable model to determine the minimum energy structures each favored. Ab initio calculations were done on several minima for ~H2O!12 to determine their relative energies. The polarizable model prefers cagelike structures for all cluster sizes, w...

The isotopically enriched cyanide anion, (13C≡15N)−, has a great potential as the NMR probe of non-covalent interactions. However, hydrogen is highly toxic and can decompose explosively. It therefore desirable to be able theoretically estimate any valuable results certain experiments in advance order carry out experimental studies only for most suitable molecular systems. We report effect bondi...

in this paper, a general elastoplastic-damage constitutive model considering the effect of strain rate has been developed. the derivation of this model has been cast into the irreversible thermodynamics with internal variables within the fundamentals of continuum damage mechanics (cdm). the rate effect has been involved as an additional term into the plastic yield surface (dynamic plastic yield...

Electronic transitions in the ultraviolet and visible spectral range can reveal a wealth of information about biomolecular geometry and interactions, such as those involved in protein folding. However, the modeling that provides the necessary link between spectral shapes and the structure is often difficult even for seemingly simple systems. To understand as to how conformational equilibria and...

Molecular dynamics simulations based on a novel polarizable nanotube model were performed to study the dynamics in translocation of a single-stranded deoxyribonucleic acid oligonucleotide through a polarized carbon nanotube membrane by an applied electric field. The study revealed a nonlinear dependence of translocation velocity and an inverse quadratic dependence of translocation time on the e...

the main purpose of this research is to investigate computationally the tautomeric reaction pathway of 5-methyl-3-methylthio-1,2,4-triazole from the thermodynamical and mechanistical viewpoints. in this respect, density functional theory (dft) in conjunction with the quantum theory of atoms in molecule (qtaim) has been employed to model the energetic and electronic features of tautomeric mechan...

The generalized effective-medium theory of induced polarization (GEMTIP) is a newly developed relaxation model that incorporates the petro-physical and structural characteristics of polarizable rocks in the grain/porous scale to model their complex resistivity/conductivity spectra. The inversion of the GEMTIP relaxation model parameter from spectral-induced polarization data is a challenging is...

The pKa's of substituted thiols are important for understanding their properties and reactivities in applications in chemistry, biochemistry, and material chemistry. For a collection of 175 different density functionals and the SMD implicit solvation model, the average errors in the calculated pKa's of methanethiol and ethanethiol are almost 10 pKa units higher than for imidazole. A test set of...