page_title: Multipole density formalism
hierarchical_section_title: Multipole density formalism
caption_attribution_description: English: Isosurface of electron density for doxycycline resulting from Multipole Model refinement at 1.5A/e^3 level.
context_page_description: The Multipole Density Formalism is an X-ray crystallography method of electron density modelling proposed by Niels K. Hansen and Philip Coppens in 1978. Unlike the commonly used Independent Atom Model, the Hansen-Coppens Formalism presents an aspherical approach, allowing one to model the electron distribution around a nucleus separately in different directions and therefore describe numerous chemical features of a molecule inside the unit cell of an examined crystal in detail.
context_section_description: The Multipole Density Formalism (also referred to as Hansen-Coppens Formalism) is an X-ray crystallography method of electron density modelling proposed by Niels K. Hansen and Philip Coppens in 1978. Unlike the commonly used Independent Atom Model, the Hansen-Coppens Formalism presents an aspherical approach, allowing one to model the electron distribution around a nucleus separately in different directions and therefore describe numerous chemical features of a molecule inside the unit cell of an examined crystal in detail.
caption: Isosurface of static electron density for doxycycline resulting from the Multipole Model refinement at 
    
      
        
          1.5
          
            
              Å
            
          
          
            /
          
          
            e
            
              3
            
          
        
      
      {\displaystyle 1.5\mathrm {\AA} /e^{3}}
    
   level.
exif: {}