Pyrazine derivatives are important class of compounds with diverse biological and cytotoxic activities and clinical applications. In this study, B3 p 86 / 6 – 31 + + G * was used to compute and map the molecular surface electrostatic potentials of a group of substituted amides of pyrazine-2-carboxylic acids to identify common features related to their subsequent cytotoxicities. Several statisti...

A time-dependent wave packet method has been developed to study atom–triatom ABC1D→AB1CD reactions in full six dimensions ~6D!. The approach employs a body-fixed coupled angular momentum basis for three angular coordinates, and three 1D bases for three radial coordinates. It permits the calculation of diatom AB vibrational state resolved total reaction probability for an initial rovibrational s...

A time-dependent wave packet method has been employed to calculate the state-to-state reaction probability for the H1H2O~0,0,0!→H2~v1 , j1!1OH~v2 , j2! reaction for J50 and initial nonrotating H2O on the modified Schatz–Elgersman potential energy surface in full six dimensions ~6D!. Starting from a wave packet for an atom–triatom asymptotic state in atom–triatom Jacobi coordinates, we transfer ...

Pyrazine derivatives are important class of compounds with diverse biological and cytotoxic activities and clinical applications. In this study, B3 p 86 / 6 – 31 + + G * was used to compute and map the molecular surface electrostatic potentials of a group of substituted amides of pyrazine-2-carboxylic acids to identify common features related to their subsequent cytotoxicities. Several statisti...

The importance of rotational transition rates in the analysis of cold interstellar clouds is well known. We present results, for temperatures ranging from 5 to 80 K, for the hyperfine-resolved rotational transitions of DCO+ induced by collision with helium. Since the isotopic substitution is not expected to introduce significant changes, close-coupling calculations are based on a potential ener...

The crossed beams reaction of the phenyl radical (C6H5) with 1,2-butadiene (CH3HCCCH2) was studied under single collision at two collision energies. The crossed beams data were combined with electronic structure calculations on the C10H11 potential energy surface. The reaction was found to follow indirect scattering dynamics via an addition of the phenyl radical with its radical center to the s...

The stereodynamics of the Ar þ NO ( j1⁄4 0) rotational inelastic excitation has been investigated at 66 meV by means of quasiclassical trajectories on a recent ab initio potential energy surface. A marked correlation between the preferred sense of rotation of NO and the scattering plane is obtained for the highest rotational levels accessible, which are excited in strong repulsive collisions. T...

A new method is proposed for locating saddle points on potential energy surfaces. The method involves walking on the ridge separating reactants’ and products’ valleys toward its minimum, which is a saddle point in coordinate space. Of particular advantage for ab inirio calculations, the ridge method does not require evaluation of second derivatives of the potential energy. Another important fea...

We study the effect of a spatially varying potential energy surface on the self-organization of nanoscale patterns during epitaxial growth. The computational approach is based on the level set method. Our results have an implication for guided self-assembly of nano patterns, which is a promising new technique for many technological applications. Both kinetic as well as thermodynamic effects can...

The cumulative reaction probability (CRP) (the Boltzmann average of which is the thermal rate constant) has been calculated for the reaction H,+OH++HzO+H in its full (six) dimensionality for total angular momentum J=O. The calculation, which should be the (numerically) exact result for the assumed potential energy surface, was carried out by a direct procedure that avoids having to solve the co...