This page remains available mainly as an historical document

Most or all of the features are no longer available via the CDS/DL website since provision of the EPSRC UK national Chemical Database Service has been taken over by the Royal Society of Chemistry from 1st January 2013.

Some related features may be available via the RSC/CSD portal. For details of what is currently available on the CDS/DL website and also links to the RSC/CDS portal follow the link to the CDS/DL Homepage.

The information below was produced before January 2013 and may be incorrect at the present time.

Secure Shell

Secure Shell (SSH) is a replacement for older methods of accessing remote computers. Protocols such as telnet, FTP and rlogin are considered to be insecure and are no longer supported on the CDS servers.

You also need X-Windows to use programs such as PeakQuest, ConQuest, Mogul, etc.
When an X-Windows server is started on your workstation, SSH can also be used to send associated data traffic in a secure manner (X11 forwarding). You may need to use X11 forwarding to get data through your local institution's firewall.

SSH for Unix/Linux and the Mac

All UNIX/Linux and Mac systems (running OSX) should already have SSH installed and support the ssh command. You will be able to access the CDS by opening a terminal window (for Macs from Applications:Utilities). Type "ssh -X", where cxxx is your CDS ID.

The "-X" option is used to allow X11 forwarding. If you encounter problems try [e.g. Mac OX 10.4 (Tiger)] you may need to use "-Y" in place of "-X" in the above command.

The sftp is used for secure transfer of files (SFTP) between a local and a remote computer. Use of the less secure FTP protocol is no longer supported on CDS servers.

SSH for the Windows PC



Transferring Files

SSH for UNIX/Linux

These operating systems should already be able to login securely via slogin (ssh).
If not, then have a look at the OpenSSH website

Configuring PuTTY

Double click putty.exe to open up a PuTTY Configuration window.

PuTTY  Sessions Configuration window

Highlight the Sessions menu (if not presented at start-up) and type in the Host name ( and click the radio button for SSH.
You could also add a Saved Session name such as CDS.

Highlight the SSH menu option (under Connections) and choose 2 as the Preferred SSH protocol version

PuTTY SSH Configuration window

[You may want to go back to Session and save it at this point]

Click on the Open button to start the secure telnet session.

Setting up X11 forwarding when using PuTTY

Click the box to Enable X11 forwarding
(In older versions up to Version 0.57 this is under the Tunnels menu option)

PuTTY Tunnels Configuration window

To test that you can get an X-Window, start an X server
(see our related webpage for further details) then type xlogo.
You should see a small box similar to the one to the right

Go back to Session, give the session a name and save it. Next time you open PuTTY just Load your saved session.