Octahedral Electron Geometries (AX6, AX5E,
and AX4E2)
Molecules in this category may have five, six or seven atoms. The
configuration is specified as AX6 for the case with seven
total atoms, AX5E for the case with six atoms and AX4E2
for the case with five atoms. Remember the "E" represents
electron groups that are not involved in bonding, the "X" atoms around
the central atom and the "A" is the central atom. Molecules of
the type AX6 are described as having an octahedral
molecular geometry, those of the type AX5E
as a square-pyramidal molecular geometry, and those of the type AX4E2
as a square-planar molecular geometry.
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Example AX6 Molecules (octahedral)
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Example AX5E Molecules (square-pyramidal)
Note how loan pairs repel bonds decreasing the bond angle to < 90°.
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Example AX4E2 Molecules (square-planar)
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Reference and Technical Info
* Measured geometry (from spectroscopic measurements) sourced from:
The NIST Computational Chemistry Comparison and Benchmark Database
NIST Standard Reference Database Number 101
Release 22, May 2022, Editor: Russell D. Johnson III
https://cccbdb.nist.gov/
Other geometries are based on estimates from quantum computations.
Last Update: July 25, 2026
Expires: --
J. Gutow
Expires: --
J. Gutow