Buscar
Mostrando ítems 81-90 de 10815
An unusual mulinane diterpenoid from the Chilean plant Azorella trifurcata (Gaertn) Pers
(Royal Society of Chemistry, 2014)
Four new mulinane-type diterpenoids besides the known compounds mulin-11,13-dien-20-oic acid, 13α-hydroxyazorellane, 13β- hydroxyazorellane, mulinolic acid, azorellanol, and mulin-11,13-dien-18-acetoxy- 16,20-dioic acid ...
Chemical bonding and reactivity: A local thermodynamic viewpoint
(Elsevier, 1999)
The possibility of gaining insight into chemical bonding and reactivity through various local temperatures and associated entropy densities is explored. Comparisons of these quantities with other local reactivity descriptors ...
Basis set superposition error in atomic cluster calculations
(Elsevier, 1999)
In this work, the basis set superposition error (BSSE) has been analyzed for the systems Cu2, Cu3, Cu6 and Cu13 as prototypes of metallic clusters. Various basis sets have been tested. In addition, pseudopotentials of 1- ...
Effect of double or single bonding in C–H stretching signal propagation in organic molecules. A computational study
(Elsevier B.V., 2019)
© 2018The objective of this study is to evaluate vibrational energy propagation of a C–H stretching signal on unsaturated organic molecules and the effect of saturation in a specific site of those molecules using ab-initio ...
Sigma-pi separation of the electron localization function and aromaticity
(2004)
The electron localization function (ELF) has been separated in its sigma and pi components. The topological analysis of the new ELFsigma and ELFpi functions has been used to quantify the concept of resonance. The highest ...
The Fukui potential is a measure of the chemical hardness
(2011)
The chemical hardness is, after the chemical potential, the most important concept in describing the chemical reactivity of atoms and molecules. Recently, we showed that the Fukui potential at the nucleus of an atom is ...
Pseudopotential calculations on the ground state of the alkaline-earth monohydride ions
(1987)
The ground state potential energy curves of alkaline-earth monohydride ions have been investigated. A pseudopotential formalism including a corepolarization potential has been used. For the valence correlation energy a ...
Calculated geometry and paramagnetic hyperfine structure of the Cu7 cluster
(2004)
All-electron spin polarized DFT calculations have been performed to optimize the pentagonal bipyramidal (D5h) geometry of the Cu7 cluster by using the B3LYP and the B3PW1 functionals with different basis sets. Dirac ...
Energy, chemical potential and hardness profiles for the rotational isomerization of HOOH, HSOH and HSSH
(1999)
A theoretical study is reported of the mechanisms for internal rotation of hydrogen peroxide (HOOH), hydrogen thioperoxide (HSOH) and hydrogen persulphide (HSSH). Calculations at the ab initio HF//6-311G** and MP2//6-311G** ...
A shell model for cross relaxation in elpasolite crystals: application to the 3P0 and 1G4 states of Cs2NaY1-xPrxCl6
(1995)
A model for cross relaxation in high symmetry systems is developed. The positions of all acceptor ions and all multipole-multipole interactions may be included. The geometric factors are explicitly considered. A feature ...