Molecular fragment electric moments derived from the fit of the experimental electrostatic potential. Application to the water molecule.
The electrostatic potential is a multicenter property that can be expressed as a sum of the contributions of electric moments located at each atomic site of a molecule. Independently of the model used to generate the electrostatic potential around the system, these atomic moments can be accurately obtained by the fit of this physical property outside the van der Waals envelop. However, the larger the system, the greater the number of parameters. In this study a way is proposed to reduce the number of centers in the representation of the electrostatic potential which becomes a sum of fragment contributions rather than atomic ones. A sample of six water molecules in different crystal environments was chosen to discuss the derived values of the electric moments referred to the molecular center of mass.
Laboratoire de Cristallographie et Modélisation des Matériaux Minéraux et Biologiques, LCM3B, UPRES A CNRS 7036, Université Henri Poincaré, Nancy 1, Faculté des Sciences, Boulevard de Aiguillettes, BP 239, 54506 Vandoeuvre-lès-Nancy CEDEX, France, and Laboratoire des Sciences des Matériaux, LSM, Université Cadi Ayyad, Faculté des Sciences Semlalia, Boulevard Prince Moulay Abdallah, BP S15, 40000 Marrakech, Morocco.
N
Bouhmaida
NE
Ghermani
C
Lecomte
A
Thalal