with the series of distinct closed loops in Fig. 7.15 for a flow with D 3h ðC 3h Þ
magnetic symmetry and Fig. 7.17 for a flow with D 3d ðS 6 Þ magnetic symmetry. The
corresponding SGs are shown in Figs. 7.14 and 7.16.
The C 3v ðC 3 Þ magnetic subsymmetry, Eq. 7.78, is observed in methane for B
along a C–H bond, taken to lie in the z direction. The corresponding SG is reported
in Fig. 7.18. The cage of SLs about a C nucleus is a transferable pattern, compare
for that observed for ethane in Figs. 7.14 and 7.16. Four (0, 0) branching points
occur along the threefold axis, at P Æ1 ¼ Æ0:66, P Æ2 ¼ Æ0:50 bohr from the origin
on the C nucleus [102]. The corresponding streamline map is displayed in Fig. 7.19.
Fig. 7.16 Perspective view
of the stagnation graph of the
current density vector field in
staggered ethane C 2 H 6 , with
magnetic symmetry D 3d ðS 6 Þ.
The uniform external
magnetic field B is parallel to
the C–C bond axis
7 Topology of Quantum Mechanical Current Density …
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