A Simple Potential Model Criterion for the Quality of Atomic Charges

Oliveira, Anselmo E. de; Guadagnini, Paulo H.; Haiduke, Roberto Luiz Andrade; Bruns, Roy E.

doi:10.1021/jp984777e

Cited by 38 publications

(39 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In a previous work, de Oliveira et al 29 reported an investigation testing the quality of Mulliken and Bader charges. They found a good agreement between both methods for a qualitative description of the atomic charges.…”

Section: Methodsmentioning

confidence: 99%

Bonding interactions of metal clusters [Mn (M= Cu, Ag, Au; n=1-4)] with ammonia. Are the metal clusters adequate as a model of surfaces?

Martínez¹

2005

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Cálculos de densidade funcional (B3LYP/LANL2DZ) para clusters metálicos de amônia foram efetuados para obter comprimentos de ligação, modos de estiramento vibracional M-N, energias de ligação, cargas atômicas de Mulliken e potenciais adiabáticos de ionização. Os resultados indicam que átomos de cobre formam ligações mais intensas com amônia do que com prata ou ouro. A interação da ligação Ag n com amônia é a mais fraca de todos os sistemas. A ligação das moléculas de amônia à clusters metálicos é comparável à de sistemas piridina-M n. Ambas moléculas apresentam uma interação dativa do par de elétrons isolado no átomo de nitrogênio. Cargas atômicas de Mulliken mostram uma pequena transferência de carga da molécula NH 3 para o átomo metálico ou cluster, sugerindo a formação da ligação dativa. Depois da transferência de carga da molécula de amônia, os clusters metálicos sofrem uma redistribuição das cargas e isto pode ser importante na estabilização do sistema. Na superfície, a redistribuição de carga deve ser menos significativa. Nesse sentido, o uso de clusters metálicos como modelo de superfície pode ser um modelo inadequado.Density Functional (B3LYP/LANL2DZ) calculations for ammonia metal clusters were done in order to obtain bond lengths, M-N stretching vibrational modes, binding energies, Mulliken atomic charges and adiabatic ionization potentials. The results indicate that copper atom forms stronger bonds with ammonia than silver or gold. The bond interaction between Ag n and ammonia is the weakest of all the systems. The bond of the ammonia molecule to the metal clusters can be compared with the pyridine-M n systems. Both molecules present a donation interaction from the lone-pair of electrons on the nitrogen atom. Mulliken atomic charges show a small charge transfer from the NH 3 molecule to the metal atom or cluster, suggestive of a dative bond formation. After the charge transfer from the ammonia molecule, the metal clusters undergo a redistribution of the charge and this could be important for the stabilization of the system. In a surface, the redistribution of the charge should be less significant. In this sense, the use of metal clusters as a model of the surface may be an inadequate model. Keywords: metal clusters, bond lengths, M-N stretching vibrational modes, binding energies, Mulliken atomic charges and adiabatic ionization potentials IntroductionComplexes of bare metal clusters with simple molecules are important model systems for fundamental studies of metal-ligand bonding in cluster and surface chemistry. 1-17Of particular interest is the relationship between cluster and bulk surface chemistry. In this area, Mitchell et al. 15 studied the reactions of copper and silver dimers with ammonia in the gas phase, while Chan and Fournier 17 reported a theoretical study of the binding of ammonia to small copper and silver clusters. A simple picture of the bonding mechanism was reported, and comparisons were made between ammonia adsorbed on the metal atoms and on bulk surfaces.The theoretical study...

show abstract

Section: Methodsmentioning

confidence: 99%

Bonding interactions of metal clusters [Mn (M= Cu, Ag, Au; n=1-4)] with ammonia. Are the metal clusters adequate as a model of surfaces?

Martínez¹

2005

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…[81][82][83][84] Siegbahn et al's simple potential model 85 corrected for relaxation energy of the 1s core ionization energy of the carbon atom is given by (12) where E C,1s is the carbon 1s core ionization energy, q A and q C are atomic charges, R AC is the internuclear distance between the A and C atoms and E relax is the relaxation energy for the ionization process. The first two terms in this equation can be derived from purely electrostatic considerations 85 or from quantum mechanical argument.…”

Section: Gapt Charges and Core Ionization Energiesmentioning

confidence: 99%

Review of Experimental GAPT and Infrared Atomic Charges in Molecules

Richter¹,

Duarte²,

Silva³

et al. 2016

Journal of the Brazilian Chemical Society

Self Cite

View full text Add to dashboard Cite

This review contains experimental values of polar tensors and generalized atomic polar tensor (GAPT) charges determined since the publication of the polar tensor formulism for infrared intensity interpretation in 1961. GAPT charges, also called mean dipole moment derivatives, for 167 atoms of 67 molecules are discussed and compared with infrared charges also determined completely from experimental intensities. The importance of the charge transfer and polarization dynamic contributions to the GAPT charge are emphasized as they differentiate this charge from most theoretically calculated charges. The inclusion of these dynamic contributions is shown to be necessary to provide adequate numerical descriptions of core electron ionization energy processes. These contributions are expected to be important in studies of chemical reactivity.

show abstract

“…Experimental [17] Molecule r e (Å) [10,18]. Hence, the only charges in accordance with the characteristics of all these highly ionic systems appear to be those from the QTAIM formalism.…”

Section: Qcisd/6-311g(2df)mentioning

confidence: 99%

An atomic charge study of highly ionic diatomic molecular systems

Nakazato¹,

Sá²,

Haiduke³

2009

Int J of Quantum Chemistry

Self Cite

View full text Add to dashboard Cite

Four atomic charge formalisms are compared using highly ionic diatomic molecules, such as LiF, NaF, KF, LiCl, NaCl, KCl, BF, AlF, GaF, BeO, and MgO. All calculations were done at the QCISD/6-311G(2df) level. The only formalism consistent with the characteristics of all these systems is Quantum theory of atoms in molecules (QTAIM). Absolute Mulliken charge values are small. ChelpG charges are not reliable for systems in which the atoms are largely anisotropic. Generalized atomic polar tensor values are contaminated with charge fluxes and atomic dipole fluxes and fail when these contributions are important and do not cancel each other. Finally, the charge-charge flux-dipole flux model was applied to dipole moment derivatives with QTAIM. This analysis shows that charge flux and atomic dipole flux contributions during bond stretching are almost null, except for oxides. There are also evidences that the lone electron pair at Group 13 elements in fluorides becomes less localized as the bond is stretched.

show abstract

A Simple Potential Model Criterion for the Quality of Atomic Charges

Cited by 38 publications

References 43 publications

Bonding interactions of metal clusters [Mn (M= Cu, Ag, Au; n=1-4)] with ammonia. Are the metal clusters adequate as a model of surfaces?

Bonding interactions of metal clusters [Mn (M= Cu, Ag, Au; n=1-4)] with ammonia. Are the metal clusters adequate as a model of surfaces?

Review of Experimental GAPT and Infrared Atomic Charges in Molecules

An atomic charge study of highly ionic diatomic molecular systems

Contact Info

Product

Resources

About