The cumulative reaction probability is calculated for the H,+OH+H+H,O reaction in its full (six) dimensionality for total angular momentum J=O. The calculation, which should give the (numerically) exact result for the assumed potential energy surface, yields the cumulative reaction probability directly, without having to solve the complete state-to-state reactive scattering problem. Higher angu...

Numerical studies are providing novel information on the physical processes associated to physical aging. The process of aging has been shown to consist in a slow process of explorations of deeper and deeper minima of the system potential energy surface. In this article we compare the properties of the basins explored in equilibrium with those explored during the aging process both for sudden t...

We locate putative global minima for (C60)N clusters modelled by the potential of Pacheco and Prates-Ramalho up to N=105. These minima are based on icosahedral packing up to N=15, but above this size the lowest-energy structures are decahedral or close-packed. Although structures based on the 98-molecule Leary tetrahedron, which have been inferred from experiment, are not lowest in energy for t...

Novel low-energy structures are found on the potential energy surfaces of the neutral, cationic and anionic gold clusters Au5≤n≤8(Z = 0,±1) and on the neutral potential energy surface of Au9. These structures provide new insights on the 2D ⇒ 3D transition in small neutral and charged gold clusters. It is demonstrated that the size threshold for the 2D 3D coexistence is lower for cationic than n...

Aims. Using a newly determined 5D potential energy surface for H2–H2O we provide an extended and revised set of rate coefficients for de-excitation of the lowest 10 paraand 10 orthorotational levels of H2O by collisions with para-( j = 0) and ortho-H2( j = 1), for kinetic temperatures from 5 K to 20 K. Methods. Our close coupling scattering calculations involve a slightly improved set of couple...

In this work, by using density functional theory, the adsorption of Nitramide (NH2NO2) molecule on the surface of pristine, B, As and B&As doped (4,4) armchair aluminum nitride nanotube (AlNNTs) is investigated. From optimized structures the adsorption energy, deformation energy, natural bond orbital (NBO), atom in molecule (AIM), quantum parameters, reduced density gradient (RDG) and molecular...

nanoparticles made of biodegradable polymers has become the best approach for nanoparticle making due to their compatibility with the human body. new glycerol adipate polymers with hydroxyl group substituted with different percent of acyl group, sited as figures within the abbreviated name in the text, and triptophan were synthesized and proposed to be used in the preparction of dexamethason ph...

We report here a refinement of the potential energy surface for the electronic ground state of the H2S molecule in a least-squares fit to experimental spectroscopic data. The calculations are carried out by combining an exact kinetic energy (EKE) approach to the calculation of the rotation–vibration energies of a triatomic molecule with the MORBID approach, which employs an approximate kinetic ...

Using ab initio unrestricted Hartree−Fock, restricted open-shell Hartree−Fock, and fourth-order perturbation theory methods, 13 minima on the Si2CH4+ potential energy surface have been calculated including ion−molecule complexes, Si−H and C−H insertion products, and other Si2CH4+ isomers. The transition states connecting those isomers have been located and the minimum energy paths have been tra...

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...