Overlap type
Picture
Combination
Show
Re–Re bond eclipsed
Bond order 4
0nodal planes
containing axis
100%overlap
this type
σ²π⁴δ²8 d electrons
(2 × Re³⁺ d⁴)
Left: Re–Re levels, 8 electrons. Right: overlap against twist — σ and the π pair are cylindrical, δ falls as cos 2χ.