Cn3D macromolecular structure viewer
Downloading Cn3D 4.1 (earlier release) for Unix

Unfortunately, NCBI can no longer support a Unix version of the newest Cn3D software. However, an earlier release, Cn3D 4.1 for Unix, is still available from this page by following the instructions below.

Download the appropriate version:

  • Solaris. Requires Solaris 7 or higher, and Solaris OpenGL.

  • i386 Linux. Requires system-installed shared libraries of GTK 1.2.7 - 1.2.10, and standard image libraries (libpng, libz, libjpeg, libtiff).

  • SGI IRIX. Requires IRIX 6.5, R5000 or higher CPU.

Then complete the following to extract and install Cn3D:

  • Unzip the archive with gunzip Cn3D-4.1.????.tar.gz  (if your system doesn't have gunzip, use gzip -d ... instead).

  • Type tar -xvf Cn3D-4.1.????.tar to extract the Cn3D-4.1  folder, which will contain the Cn3D executable, the data directory, and the help file.
  • Set the CN3D_HOME environment variable to your Cn3D-4.1 directory. For example, if you are using (t)csh, you can put setenv CN3D_HOME /home/myuserid/Cn3D-4.1 in your .cshrc file.

  • Optionally, you can put Cn3D in your $PATH, for convenient startup.

Once done, see the instructions on configuring your browser.

Newer Versions of Cn3D
  A new version of the program, Cn3D 4.3.1, is available for the PC and Macintosh.

For Unix users who would like to take advantage of the program's newer features, Cn3D can be built as part of the NCBI Toolkit, which contains the Cn3D source code and make files (requires wxWidgets). A number of documents, including an electronic book, provide additional details about the Toolkit.

Revised 20 September 2016