ChemShell Availability and Licence

Two versions of ChemShell are available depending on which scripting language is used to control the code, Python or Tcl.

The current standard version of ChemShell is Tcl-ChemShell, and for most users (especially new users) this is the version that we recommend for production calculations at present, although it will eventually be superseded by Py-ChemShell.

Obtaining Py-ChemShell

The Python-based version of ChemShell is open source software and available free of charge from this website. The latest beta release (v20.0) is available for download here (please register a website account to access the download page).

We regard Py-ChemShell 20.0 as suitable for production calculations on materials systems, although some features from Tcl-ChemShell are not yet available. We do not currently recommend Py-ChemShell for calculations on biological systems, as automated import of biomolecular force fields is scheduled for a future release.

Obtaining Tcl-ChemShell

The original Tcl-based version of ChemShell is licenced under a proprietary STFC licence. We are distributing the latest version of the code (v3.7) to academic research groups on receipt of a completed licence agreement and (in the case of non-UK licencees) a licence fee of 500 UK Pounds. The license covers the ChemShell code, not the standalone quantum chemistry or MD codes to which ChemShell provides interfaces.

You can download a copy of the Academic Licence form which should be completed, scanned and emailed to Tom Keal. For payment details please see ChemShell payment instructions. In case of any problems making the payment, please contact Damian Jones.

UK academic groups should use the Royalty Free licence and do not need to make a payment.

Please note that no changes can be made to the academic or royalty free licence terms and conditions.

For commercial licencing of Tcl-ChemShell, or for any further information please contact Tom Keal.