Electron density and electrostatic potential of KNiF₃: multipole, orbital and topological analyses of vacuum-camera-imaging plate and four-circle diffractometer data

The electron density and electrostatic potential of KNiF₃, nickel potassium trifluoride, were studied using multipole and orbital model treatment of the precision X-ray diffraction data measured by vacuum-camera-imaging plate and four-circle diffractometer methods. Different experimental methods lead to similar multipole and atomic displacement parameters and to qualitatively the same electron densities. Good agreement was also achieved for the Laplacians of the electron density and the electrostatic potentials. Some pitfalls of the vacuum-camera-imaging plate method that could be improved are discussed.