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, and is only updated for critical maintenance. Chimera development was supported by a grant from the National Institutes of Health (P41-GM103311) that ended in 2018.

Feature Highlight

Multiscale Models

The Multiscale Models extension allows Chimera to display large complexes such as virus capsids, ribosomes, and chromatin. It displays the quaternary structure of PDB models and allows subunits to be selected and shown in atomic detail. Matrices are read from PDB files that specify the biological unit. Crystallographic packing can also be shown.

(More features...)

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Gallery Sample

Wasabi Receptor

The image shows the structure of the human TRPA1 ion channel (wasabi receptor) determined by electron cryo-microscopy, Protein Data Bank entry 3j9p. The four subunits of the tetramer are shown as ribbons in different colors over a dark-to-light gradient background. (More samples...)