# Bond-angle analysis

This modifier identifies the local environment of particles using the Ackland-Jones bond-angle method [Ackland and Jones, Phys. Rev. B 73, 054104] and assigns a structure type (FCC, BCC, HCP etc.) to each particle.

In addition to assigning colors to particles, the modifier stores its results in the `Structure Type` particle property. The coordination structure types are encoded as integer values:

- 0 = Other, unknown coordination structure

- 1 = FCC, face-centered cubic

- 2 = HCP, hexagonal close-packed

- 3 = BCC, body-centered cubic

- 4 = ICO, icosahedral coordination

Note that this modifier requires access to the complete set of particles to perform the analysis. It should therefore be placed at the beginning of the processing pipeline, preceding any modifiers that delete particles.