What a Lewis structure shows
- Which atoms are connected
- Single, double and triple bonds
- Lone pairs and unpaired electrons
- Formal charges
- Resonance contributors
Capability note: the current tool is not an interactive 3D Lewis structure generator. It displays stored 2D diagrams plus geometry names and representative bond angles for supported records.
What a 3D molecular model shows
- Spatial atom arrangement
- Approximate bond angles
- Molecular symmetry
- Wedge-and-dash orientation
- Steric relationships and conformation
How to convert a Lewis structure into a 3D shape
- Draw a valid Lewis structure.You need the correct central atom, bonds and lone pairs before applying VSEPR.
- Count electron domains around the central atom.Every single, double or triple bond counts as one domain. Every lone pair counts as one domain.
- Assign the electron-domain geometry.Two domains are linear, three trigonal planar, four tetrahedral, five trigonal bipyramidal and six octahedral.
- Ignore lone pairs when naming molecular geometry.For example, four domains with two lone pairs give a bent molecule, not a tetrahedral molecular shape.
- Adjust approximate bond angles.Lone pairs repel more strongly than bonding pairs and usually compress nearby angles.
VSEPR geometry reference
Examples where the 2D drawing can mislead
CH4
A cross-shaped page drawing is not square planar. Four domains produce a tetrahedron.
H2O
The H–O–H drawing may look linear, but two oxygen lone pairs make the molecule bent.
NH3
Three N–H lines can look planar on paper, but the nitrogen lone pair produces a pyramid.
Electron geometry vs molecular geometry
Electron geometry includes both bonds and lone pairs. Molecular geometry describes only atom positions. Water therefore has tetrahedral electron geometry but bent molecular geometry. Ammonia has tetrahedral electron geometry but trigonal pyramidal molecular geometry.
Does hybridization equal geometry?
Hybridization labels such as sp, sp² and sp³ are simplified bonding models often correlated with domain count. They can be useful in introductory chemistry, but they should not be treated as literal, directly observed shapes in every molecule—especially for hypervalent species.
Common mistakes
- Calling a molecule's page layout its three-dimensional geometry.
- Counting a double bond as two VSEPR domains.
- Ignoring central-atom lone pairs.
- Using the electron geometry name when the question asks for molecular geometry.
- Claiming a 2D Lewis diagram is an interactive 3D model.
Last reviewed: July 15, 2026.