Electronic Supplementary Information (ESI)

The Royal Society of Chemistry's Electronic Supplementary Information (ESI) service is a free facility that enables authors to enhance and increase the impact of their articles. Such data can take full advantage of the electronic medium, allowing use of full colour diagrams, 3D molecular models and even movies. Authors can also improve the readability of their articles by placing appropriate material, such as repetitive experimental details and bulky data, with the ESI service. All information in the ESI service is also fully archived.

Help on Preparing and Viewing ESI

Authors are encouraged to make the most of the benefits of publishing supplementary information in electronic form. These notes outline how to prepare and view such data.

For those who are new to electronic publishing, a detailed tutorial on how to view and get the best from these features is available.

How to prepare Electronic Supplementary Information

Authors wishing to submit electronic supplementary information for an article should, where possible, supply data in the following file types. Other formats may be supplied, and every effort will be made to use these where possible. It is intended that the ESI system should make full use of developing file types to allow authors to present their data in the most useful and interesting ways possible. If you are providing an unusual file type, please provide the Editorial Office with details of any additional software that would be required to view the files. Such software should be available freely, preferably via the web.

Examples of the various types of data that can be made available as ESI can be viewed by following the links in the file types listed below.

Graphical Files

Authors are encouraged to make full use of colour when submitting graphical files. However, as the files are to be viewed electronically, the maximum size should not exceed 640x480 pixels. An example of a full colour molecular orbital diagram (in this case a JPEG file) that has previously been deposited as ESI can be seen below.

The following formats for graphical files are preferred, and some additional examples can be found by following the links from the file types:

Text Files

Please provide text files in one of the following formats. The first two file types also contain links to good examples of where the ESI service was utilised to place bulky data and additional experimental details.

Crystallograhic Information Files (CIFs)

CIFs should be submitted to the appropriate editorial office via e-mail at the time of submission of the manuscript (as per Instructions for Authors of the relevant journal). All CIFs will automatically be placed on the ESI service upon publication of the article. Authors are also encouraged to use their CIFs to produce 3D molecular files (as described below).

Click here for an example CIF file

3D Molecular Information Files

Authors presenting molecular coordinates from crystallographic or modelling studies as ESI can benefit from providing such results in Brookhaven protein databank (PDB), MDLI Molfile or xyz format. While coordinates provided by most crystallographers normally come in SHELX format, conversion of SHELX to PDB can be easily accomplished using SHELX93, Chem3D or Babel. The crystallographer, however, must ensure that all the molecular coordinates are written out (not just the unique asymmetric atoms), when the file is created.

The resulting text file will look like this

However, when viewed with the ChimeTM plug-in, a 3D image will be displayed, as can be seen in this MOL file example. Holding the mouse arrow over the molecule allows the viewer to rotate the molecule to investigate it in greater detail. Additionally, the reader can change the look of the molecule by choosing spacefill, ball and stick etc. formats for the molecule. It is even possible to introduce animation, as can be seen in the XYZ file example below.

Acceptable file types include:

A tutorial showing some easy methods to produce 3D figures in such formats is available here

Three dimensional images

3D images of, for example, results from molecular modelling or molecular orbital calculations can be displayed as 3D images which allow readers to rotate, zoom in etc. to inspect the figures more closely. Some figures can be viewed using the Chime Plug-in, or, in the case of the VRML example linked to below, by using Cosmoplayer.

Acceptable file types include:

Spectra etc.

Certain software packages allow spectra, HPLC traces etc. from a spectrometer to be saved in the JCAMP-DX format. The file specifications for some of these packages are available free from the IUPAC Working Party on Spectroscopic Data Standards (JCAMP-DX) website. Plots in JCAMP-DX format can then be displayed using the Chime plug-in and expanded and manipulated on screen. Providing JCAMP-DX files allows readers to save spectra for direct comparison with their spectra.

Please submit spectra in the following file type. Clicking on this link will display an example spectra which can be manipulated on screen.


Dynamic processes can be presented in the electronic medium easily and effectively. Authors are encouraged to provide movies as ESI in those instances where a static image will not satisfactorily convey the information presented. Authors are requested to prepare their movies in commonly used formats, such as mpeg, or quicktime. Since movies tend to use a lot of memory, authors are requested to keep such presentations as small as possible, in order to reduce download times for readers. The appropriate file extension should be attached to each video file, for example .qt or .mov for quicktime, .mpeg for mpeg, etc.

Acceptable file types include the following. Click on each link to see an example movie:

How to access ESI

In order to view or download the electronic supplementary data you will require Netscape Navigator (3 or above) or Microsoft Internet Explorer (4 or higher). Some of the file types supported can be viewed directly by your web browser. These are the graphical files (.jpeg and .gif) and the crystallographic information files (.cif). In addition certain file types will require additional software 'plug-ins' in order to be viewed. These can be downloaded from the appropriate links and, once installed, will allow you to view that file type from within your web browser.

There are several ways to access the ESI corresponding to a paper: