VSEPR Theory
... brought to you by Dr. McCord

the FIVE core electronic geometries

These are the 5 core geometries that all VSEPR theory is based on. There are another 6 geometries that are subsets of these five. The subsets are made by substituting electron lone pairs into the positions instead of atoms.

Click on any of the geometry names to open a page about that geometry and all its subsets.

linear

formula: AX2
hybridization: sp
angle: 180°
examples: BeCl2, CO2, C2H2

180°

trigonal planar

formula: AX3
hybridization: sp2
angle: 120°
examples: BH3, H2CO, NO3, C2H4

120°

tetrahedral

formula: AX4
hybridization: sp3
angle: 109.5°
examples: CH4, SO42–, C2H6

109.5°

trigonal bipyramid

formula: AX5
hybridization: sp3d
angles: 180°, 120°, 90°
examples: PF5, AsCl5

120° 180° 90° axial equatorial

octahedral

formula: AX6
hybridization: sp3d2
angles: 180°, 90°
examples: SF6, SeCl6

90° 180°