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

Chemical Knowledge

• determination of atom types in arbitrary molecules, including non-standard residues
• ability to add hydrogen atoms
• high-quality hydrogen bond identification
• selection of atoms/bonds by element, atom type, functional group, amino acid category
• interactive bond rotation, distance and angle measurements

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Gallery Sample

RNA Bases

Large ribosomal RNA is shown with individual bases depicted using solvent excluded molecular surfaces. Bases A, C, G, U are colored red, yellow, green, and blue. The surfaces were made with the Chimera multiscale tool in combination with the nucleic acid blobs plug-in. The image was raytraced using POVray.

Protein Data Bank model 1s72.

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