| The SCF-MO solution for
C9H9+ |
| 28b (Hückel), -13.9eV |
29a (Möbius), -13.3eV |
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- The most stable π-MO a + b pair each has
a node (phase shift) at one of the two points where the
C2 axis crosses the cycle, a pattern which is
usefully diagnostic.
- The lower energy partner has a node which lies
perpendicular to the axis (lhs) avoiding the
compressed region.
- The higher energy partner has a node which lies
along the C2 axis (rhs), encountering the
compressed region.
- Nodes mean neither MO is a Möbius surface.
- Can the Eigenvalue ordering be sensitive to the nature of the
atom(s) at the axis (C => N+)?
- Is the non-Möbius surface of the a
orbital due to C-H mixing?