Click on the icon to travel to the home page. Use the Back feature of your browser (usually a button on a menubar, or a right mouse-button click against the page background, or a hot-key combination such as Alt-LeftArrow) to return here.
The canonical address for the IUCr Home Page is
However, you may also see it written sometimes as http://www.iucr.org/iucr-top/welcome.html
This should work equally well. The iucr-top component permits more consistent naming of pages across the various mirror sites that exist (see below).
If your browser supports frames, you may obtain a possibly more useful view of the available pages by replacing the welcome.html in the above URLs by index.html, or deleting it altogether.
The Home Page contains the following components:
The home page address for a mirror site in a country whose two-letter ISO code is xx is generally http://www.xx.iucr.org/welcome.html
It is useful to familiarise yourself with the custom logo of your favourite mirror site. Hot links should always take you to another page on the same site, but occasionally you may find yourself transferred to a different location.
Note that every URL of the form http://a.mirror.host/iucr-top/something should be equivalent to a URL of the form http://another.mirror.host/iucr-top/something, permitting you to deduce the location of any page on your favourite mirror host.
This is also true for pages in the Crystallography World Wide and Sincris collections, which contain references to cww-top and sincris-top, respectively.
Many of the forms which allow you to search for further information send your request to the database servers in Chester or Paris, irrespective of which mirror you are using. However, hot links in any response to such a query should point to pages on the mirror you are using.