Isoelectronic density surface

Fig. 13 Isoelectronic density surfaces for (a), the LUMO (p = 0.0050 e A and (b), the HOMO ip = 0.0083 eA-3) in the case when orbital degeneracy is present...

Figure 9 Isoelectronic density surface of adrenaline at four different density values (a) 0.5 au (b) 0.1 au (c) 0.02 au and (d) 0.005 au...

Figure 2-125. Different isovalue-based surfaces of phenylalanine a) isoelectronic density b) molecular orbitals (HOMO-LUMO) c) isopotential surface and d) isosurface of the electron cryo-microscopic volume of the ribosome of Escherichia coii.

Electron density surfaces can also be used to uncover trends and build qualitative descriptions. For example, size surfaces for the isoelectronic molecules, methyl anion, ammonia and hydronium cation show a marked decrease in overall size. 

Figure 1.10 Isoelectronic surface of the total electron density of ammonia 2 and Irenzene 3. Note the lack of lone pairs or a it-clond. (See insert for color representation of this figure.)...

The electron density distribution is a four-dimensional function (the number of elearons at a given point (x,y,z)), which is difficult to visually represent. Figures 1 and 2, respectively, show a three-dimensional isoelectronic surface of benzene and a contour plot of the elearon density p(r) in the molecular plane of benzene. Both representations show only gross features of the density. In particular, the total electron density distribution is dominated by the core electrons and appears simply as an aggregate of slightly distorted spheres... 

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