Discussion of Daudel Contribution

Abstract

It would certainly be possible to define first some ‘individual loges’ without partitioning the physical space into non-overlapping boxes. Let us consider a very small volume near the center of a chemical bond, and the mean number of particles in this volume and its fluctuation, or its entropy. If the volume is very small, as shown by Diner in his previous talk, the fluctuation is large. If we enlarge this volume around one nucleus of a diatomic bond (H2 for instance) the fluctuation remains important: in the ground state of the H2 molecule for a non-correlated wave-function, the neutral situation Open image in new window which is identical to the mean situation) is not more frequent then the ionic situation Open image in new window and Open image in new window , and the fluctuation of the number of particles in the half-bond is large. The correlation does not change the situation dramatically and one may suppose that the statement is true for any single bond between two atoms of a molecule. If the volume is enlarged towards the chemical bond loge, the fluctuation diminishes. nearly always one find 2 electrons in the bond, the ionic situations with 3 (or more), 1 or zero electrons are not frequent in general (at least for the saturated compounds). But if we still enlarge the volume to include in it half of a neighbouring bond the fluctuation of the number of electrons around its mean value 3 will be large, the situation with 2 or 4 electrons being highly probable.