Collaborative Computational Project No. 4
Software for Macromolecular X-Ray Crystallography

CCP4i: The CCP4 Graphical User Interface

There is a separate programmers page with links to documentation and other useful information:


Documentation for the current release version of CCP4i

Background and history

Since 1997 Liz Potterton has been developing a graphical user interface for the CCP4 suite. The interface, christened ccp4i, was first made publicly available sometime in 1998, and has been released as an official part of the main CCP4 suite since March 1999 (CCP4 4.0).

In March 2001 Liz moved on to the CCP4 3D Viewer Initiative and support and development of CCP4i has passed onto CCP4 staff.

Current and related developments

The new features in the most recent version of CCP4i (released with the 6.0.* version of CCP4) are described in a CCP4 newsletter article:

A number of new projects are currently being planned, some of which are described briefly on a separate CCP4i Projects page.

Please contact CCP4 if you would like to know more about these developments.

Problems with CCP4i

Known bugs and fixes for the current version of CCP4i can be found on the CCP4 Problems Pages.

More general CCP4i problems can be found on the Trouble Shooting page.

Reporting problems

Please report bugs and problems with CCP4i to (or use the "Mail CCP4" button on the Main Window).

To help us solve your problem send us as much information as possible:

We will initially try to run the task with the same parameters as you but with our own data, however this may not always be possible.

If you are concerned about confidentiality: the def file does not tell us anything about your data except the file names - if you like then you can edit the def file to change the name of the files (do not delete them completely as this will make it more difficult to solve the problem).

Sometimes it can also be useful to examine the "session log" that CCP4i generates while it is running. This is a text file which is created in the user's CCP4 directory. For UNIX and Linux-type systems this is typically:

For Windows based systems it is normally:

Tcl/Tk/BLT Information

It is recommended that CCP4i be run using the bltwish interpreter, with the Tcl/Tk version 8.4.

The CCP4 download pages have the option of downloading and installing the current versions of Tcl/Tk and BLT as part of a CCP4 installation.

Alternatively, source and binary bundles for all three packages can be downloaded from the CCP4 ftp server, at

More information about CCP4i and Tcl/Tk/BLT can be found in the CCP4i installation instructions. A separate page also details known problems installing Tcl/Tk/BLT.

Useful Webpages:

New CCP4 Interfaces

These are "official" CCP4 task interfaces which are not part of the current CCP4 distribution. These can easily be installed using the "Install Task" option in the main interface; see below.

3rd Party Interfaces

A list of interfaces to "3rd party" (i.e. non-CCP4) packages is given below. These interfaces are not distributed with CCP4 but can easily be installed using the "Install Task" option in the main interface; see below.

Please send details of new interfaces to so that they can be added to this list.

Users: how to install new interfaces

CCP4i includes an option to automatically install new tasks - use the Install New Task button in the System Administration menu (on the right hand side of the main window).

All you need then is to select the name of the .tar or .tar.gz file which has been provided by the developer for the new task, and click on the Install button. CCP4i will automatically unpack and copy the files to the correct places and add the new task to the menu in the appropriate Module.

Note that you will need to restart CCP4i for the new task to become visible. More information about the Install New Task function can be found here.

Developers: how to package up new interfaces

This information can now be found in the relevant section of the CCP4i Developers Resources page.

CCP4i-related newsletter articles

A number of articles have appeared in the CCP4 newsletter on various aspects of the interface: