The success of the empirical methods in computing the electric charge distribution in a given chemical composite is strictly dependent on the possibility to describe this last through its chemical and physical properties. For systems with known structure, some authors were able to reproduce the charge distribution on atoms in very good agreement with those worked out using ab initio calculations. This was performed by using a specific orbital electronegativity or via an exact computation of the electric potentials inside the material. On the other hand there are in literature some examples in which empirical methods are applied also in the case of amorphous materials where the structure, having a disordered character, may not be described. Due to the lack of any symmetry, it is not possible to have correct values of orbital electronagativities or correctly compute the Madelung potential, being the atom's position unknown. This article describe a novel technique to compute both the charge distribution on atoms and the electric fields generated in an amorphous systems to better understand its physical and chemical properties
Determination of the electric charge distribution in an amorphous material. II. Evaluation of the Madelung potentials and computation of the electric charges
Speranza, Giorgio
2004-01-01
Abstract
The success of the empirical methods in computing the electric charge distribution in a given chemical composite is strictly dependent on the possibility to describe this last through its chemical and physical properties. For systems with known structure, some authors were able to reproduce the charge distribution on atoms in very good agreement with those worked out using ab initio calculations. This was performed by using a specific orbital electronegativity or via an exact computation of the electric potentials inside the material. On the other hand there are in literature some examples in which empirical methods are applied also in the case of amorphous materials where the structure, having a disordered character, may not be described. Due to the lack of any symmetry, it is not possible to have correct values of orbital electronagativities or correctly compute the Madelung potential, being the atom's position unknown. This article describe a novel technique to compute both the charge distribution on atoms and the electric fields generated in an amorphous systems to better understand its physical and chemical propertiesI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
