Trigonal pyramidal molecular geometry

Trigonal pyramidal molecular geometry is a type of molecular geometry. An atom in a molecule has this geometry if it has chemical bonds connecting it to three other atoms, the outer atoms make a (roughly) equilateral triangle, and this triangle is not on the same plane as the central atom. This makes the atoms the corners of a triangular pyramid.

Trigonal pyramidal molecular geometry occurs because the central atom has one lone pair, which pushes the outer atoms and their bonds away as predicted by VSEPR theory. It is related to tetrahedral molecular geometry, which has a similar shape but with one more atom instead of the lone pair.

This short article about chemistry can be made longer. You can help Wikipedia by adding to it.

v t e Molecular geometry
VSEPR theory Coordination number
Coordination number 2	Linear Bent
Coordination number 3	Trigonal planar Trigonal pyramidal T-shaped
Coordination number 4	Tetrahedral Square planar Seesaw
Coordination number 5	Trigonal bipyramidal Square pyramidal Pentagonal planar
Coordination number 6	Octahedral Trigonal prismatic Pentagonal pyramidal
Coordination number 7	Pentagonal bipyramidal Capped octahedral Capped trigonal prismatic
Coordination number 8	Square antiprismatic Dodecahedral Bicapped trigonal prismatic
Coordination number 9	Tricapped trigonal prismatic Capped square antiprismatic
Commons