distance above and below the r h plane. The fourth paramagnetic vortex rotates about an
SL that coincides with the C 3 axis. The streamlines in Fig. 7.24 show the extension of
the paramagnetic vortex about the centre of the molecule. The corresponding contours
and three-dimensional perspective view accounting for the intensity of the current field
indicate that the central paratropic whirlpool is as weak as the diamagnetic flow in the
tail regions. There is no evidence of strong delocalized currents and of r-aromaticity on
the magnetic criterion [113, 114].
0.0
1.0
1.702
Fig. 7.24 Streamlines and modulus of the current density vector field induced by a magnetic field
of unit magnitude, normal to the molecular plane of cyclopropane and directed outward. The
distance in bohr from the origin is specified by a number on the down-left corner. Atom positions
are marked by crosses. Maximum modulus (step between two consecutive contours) in au: 2.22
(0.02) at 0.0, 0.0872 (0.009) at 1.0, and 0.0916 (0.009) at 1.702
7 Topology of Quantum Mechanical Current Density …
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