DETERMINATION OF ZERO-FLUX SURFACES AND INTEGRATED PROPERTIES FROM EXPERIMENTALLY DETERMINED CHARGE DENSITIES IN CRYSTALS. C. Flensburg, D. Madsen, S. Larsen and R.F. Stewart, ^aCentre for Crystallographic Studies,University of Copenhagen,Denmark, ^bDepartment of Chemistry,Carnegie-Mellon University,Pittsburg,U.S.A

Topological analysis of electron densities is a well established method in theoretical chemistry used to characterize atomic properties and interatomic interactions. Recently is has been shown that the topological analysis also can be applied to theoretical electron densities in crystals,. We have investigated topological features of densities determined from projection of X-rays diffraction data onto the multipole model. The number of different types of critical points (CP) in the unit cell must satisfy the Morse equation: . The asymmetric unit is scanned for places where the gradient of the electron density vanishes and sets of CP's that satisfies the Morse equation are found. A topological atom is defined as the union of an attractor and its associated basin. The basin being the volume enclosed by the surface which has zero-flux in the gradient of the charge density: We have implemented an algorithm analogue to the promega method. Results from integration of properties of topological atoms in crystals for several systems will be presented.