UCSF Chimera is a program for the interactive visualization and analysis of molecular structures and related data, including density maps, trajectories, and sequence alignments. It is available free of charge for noncommercial use. Commercial users, please see Chimera commercial licensing.

We encourage Chimera users to try ChimeraX for much better performance with large structures, as well as other major advantages and completely new features. ChimeraX includes a significant subset of Chimera features (with more to come, see the missing features list) and is under active development. Users may choose to use both programs, and it is fine to have both installed.

Chimera is no longer under active development. Chimera development was supported by a grant from the National Institutes of Health (P41-GM103311) that ended in 2018.

Feature Highlight

Metal Geometry

The Metal Geometry tool facilitates analysis of metal-binding sites. It lists potential metal-coordinating atoms (nearby nucleophilic heteroatoms) and suggests likely coordination geometries. An idealized geometry can be depicted with solid arrows, as shown in the figure for the octahedral coordination of Mn⁺⁺ by six atoms, and the coordination pseudobonds in the structure can be updated to match the chosen geometry.

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Gallery Sample

Peroxiredoxin Wreath

Peroxiredoxins are enzymes that help cells cope with stressors such as high levels of reactive oxygen species. The image shows a decameric peroxiredoxin from human red blood cells (Protein Data Bank entry 1qmv), styled as a holiday wreath.

See also the RBVI holiday card gallery.

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