Data retention

You may upload bulk and/or surface structure files into SAINT in order to use the SAINT tools on your project. For example, once uploaded you can generate surfaces from your bulk models (or from the bulk data already in the database). When you do so, the new model is retained on our web servers temporarily so that you can return to it if your connection to the site is temporarily broken. To return to a model at a later date, please remember to bookmark the page or otherwise save the URL. You may also find these models by selecting My Bulk Structures or My Surfaces when performing a search.

Temporary models cannot be found in searches by other users. However, they are not private - you may share the URL with any other person (whether they are a registered user of SAINT or not), and they will be able to access the model.

Models will be retained for at least one week but may be deleted at any point after that.

Uploading files

You may upload files to SAINT in order to work with your own bulk and surface models. At present, SAINT support uploads in CIF format, although some CIF features may not be supported. In particular, the space group can only be specified by number or short name (not full name), and only standard settings are supported. Uploaded files are stored on the web server for a temporary period.

Uploading grids

Trusted users can also upload grids of numerical data, representing measurements at different positions on a plane parallel to the surface, e.g. the electrostatic potential, or the interaction energy of a specified probe molecule. These grids must be in CSV format and contain no headers or row labels. Values will be interpreted as those at grid points that are evenly spaced across the surface of a single unit-cell. For example, if a surface has a 3×3 supercell, then a file with 9 rows and 9 columns should be interpreted as representing values at [x, y] fractional co-ordinates (0, 0) to (1/3, 1/3), with increments of 1/24 in both the x and y direction, as shown in the below diagram.

Due to periodic boundary conditions, the values at 00 and 80 (x,y = 0,0 and 0,1/3 respectively) would be the same due to periodic boundary conditions. This is also true of values at 00 and 08, and so on.

Creating surface models

From a chosen bulk phase, surface models can easily be generated. The cut for a surface can be specified by providing values for the Miller index and a location in the bulk unit cell. The latter enables the user to choose what termination is desired when there is more than one unique surface for the chosen Miller index.

When generating a new surface model, you may also request SAINT: saturate bonding (for example, for silica keep all silicon atoms four-coordinated by addition of hydrogen atoms); does not cut through molecules (as determined by comparing interatomic distances to covalent radii) for molecular crystals; or either expose or not expose metallic centres of a Metal Organic Framework. Note that these options are still under development - until complete they may return the same as the standard cut.

Please note that for ionic materials it is left for the user to ensure the surface model is appropriate (currently, SAINT does not automatically reconstruct polar surfaces – Tasker type III – in order to remove the intrinsic dipole).

Publishing models

Trusted users can publish models they have created or uploaded to SAINT. Published models will not be deleted, and will be available for all users, i.e. they can be found using the SAINT search tools.

Before publishing any model, you must ensure that you have the right to do so. Files that you have created yourself should usually be acceptable. Files that you have obtained from other databases may not be acceptable. Structural data taken from a publication can also be linked to the DOI of that paper. If in doubt, please contact the owner of the data, or contact us for assistance.

If there is data on the site that you are the owner of and feel should not be there, please contact us to discuss its removal.

Privacy & Cookies

Usage of this website is governed by UCL's General Privacy Policy.

We aim to store and transfer a minimal amount of personal data about users of the website:

The SAINT website uses cookies in order to maintain sessions and remember preferences for logged-in users. These cookies do not contain personal data, and cannot be accessed by other websites. We do not use any third-party cookies.

For more information, and for information about cookies used on other UCL websites, please see UCL's Cookie Policy.