The terms, plainly.

Terms of service

StructSub is operated by StructSub Ltd, a company registered in England and Wales (company number 17502643), registered office 71-75 Shelton Street, Covent Garden, London, WC2H 9JQ. Using the hosted service means accepting these terms.

What you may do

Upload structures, edit and analyse them and use the results - including in publications and in commercial work - subject to your plan's allowance. The scientific results are yours. No ownership is claimed over the structures you upload or the outputs you generate, and no licence over them is taken beyond what is needed to run the calculation you asked for and to store the result for you.

What you may not do

• Resell, sublicense or redistribute access to the service.
• Share one account's credentials across people the plan does not cover. A plan belongs to a workspace, and the workspace's members share its allowance.
• Attempt to circumvent the allowance, the rate limits or the download gate - including by cycling anonymous trials.
• Use the service to build a competing product, or as a source of training data for a model.

Availability

The service is provided without an uptime guarantee. It is a single deployment, not a redundant one, and it will be down for updates. If that is not acceptable for your work, the engine also runs locally.

No warranty

StructSub implements computational methods using equations and parameterisations drawn from the scientific literature. Its methods have been evaluated against published results within the scope and limitations of those studies; comparative benchmarks against other software will be reported in a forthcoming manuscript. StructSub does not perform first-principles electronic-structure calculations, such as wavefunction-based methods or density functional theory (DFT). Geometry optimisation instead uses literature-parameterised force fields and machine-learning interatomic potentials, alongside the documented models used by its other analyses. As with any simulation, results depend on the method, inputs and system studied and do not replace experimental verification. The service and its results are provided “as is”, without warranty of any kind.

Ending it

You may stop at any time (see cancellation). Accounts that breach these terms may be suspended; where the breach is not deliberate you will be told what the problem is first.

Privacy and your structures

StructSub Ltd (company number 17502643) is the controller of the personal data described here.

What is stored

What is not done with it

Your structures are used to answer your own requests and for nothing else. They are not sold, not shared with third parties, not used to train models and not read except where you ask for support and give permission, or where we are legally required to.

Card details

Payments are processed by Stripe, which acts as merchant of record. Card numbers never reach StructSub - the checkout happens on Stripe's own pages. We store a Stripe customer identifier so your subscription can be found, and nothing else about your payment method.

Processors

Three third parties process data on our behalf: Clerk (authentication), Stripe (payments) and our hosting provider. Each has its own privacy terms.

Your rights

You can ask for a copy of what is held about you, ask for it to be corrected or ask for your account and its data to be deleted. Write to the address in Contact. Deleting your account deletes your workspaces' structures; billing records are kept where the law requires them.

Data retention

What you upload is not stored beyond the session you are working in, with one exception. A structure is held in the server's memory while you edit it and is discarded once the session goes idle; it is not written to a database, and it does not survive a restart. This is the same on every plan - retention is not something a plan buys.

The exception is the result of a background calculation: adsorption, transport and mechanical properties, which can run for hours. So that you can close the tab and come back for it, the result is written to the server's disk together with the structure it ran on, and deleted automatically after the period below. Only you can list it.

Export anything you want to keep before you stop working. There is no Recent Work list to come back to, and closing the tab on an unexported edit loses it. Background calculations are listed under Jobs until they are deleted.

Backups cover the account and billing tables only, so there is nothing of yours in one. Server access logs are kept for operational purposes and are not used to profile you.

A local server - one you run yourself - behaves the same way, and nothing leaves your machine at all.

Cancellation and refunds

Cancelling

Open the account panel and choose Manage billing & invoices. That opens Stripe's own portal, where you can cancel, change your card and download invoices. There is no retention process and nobody to talk to first.

A cancelled plan runs to the end of the period you have already paid for, and the account panel says which date that is. You keep the full allowance and Guest tools until then. After that the workspace returns to the free plan, with its allowance and access rules. Guest tools require an active paid subscription, except for Remove guests. No structure of yours is stored either way.

Refunds

Cancelling stops future payments; it does not automatically refund the current period. If the service did not do what it said it would, write to us and say what happened - a refund for a period you could not use is not something you should have to argue for.

If you are a consumer in the UK or EU, your statutory cancellation rights apply in addition to anything on this page and are not affected by it.

Price changes

The price you subscribed at is the price you keep for as long as that subscription runs. A change to the published price does not reprice an existing subscriber; you would be told before anything changed.

Failed payments

If a payment fails, the account panel displays the status while Stripe retries. If payment continues to fail, the workspace returns to the free plan rather than being locked; your work remains available.

Software licence

StructSub is proprietary. Using the hosted service is licensed by these terms; the source is not licensed for use, copying or redistribution, and possession of a copy grants nothing. See the LICENSE file in the distribution for the full text.

Academic and non-commercial use is welcome and available on separate terms - ask.

StructSub depends on third-party open-source components, each under its own licence, and none of them is affected by the above. The full list, and the rule governing what may be depended on, is in docs/LICENSING.md.

Governing law

These terms and the software licence are governed by the laws of England and Wales, and the courts of England and Wales have exclusive jurisdiction over any dispute arising from them. If you are a consumer, this does not deprive you of the protection of the law where you live.

How to cite StructSub

If StructSub contributed to work you are publishing, please cite it. It costs you a line and it is the main way a tool like this stays funded and maintained.

Wonanke, A. D. D. (2026). StructSub: An Integrated Platform for Rapid Structure Building, Modification and Analysis for Chemistry and Materials Science (Version 1.0.0) [Computer software]. Zenodo. https://doi.org/10.5281/zenodo.22748601

@software{structsub2026,
  author       = {Wonanke, A. D. Dinga},
  title        = {{StructSub: An Integrated Platform for Rapid Structure Building, Modification and Analysis for Chemistry and Materials Science}},
  year         = {2026},
  publisher    = {Zenodo},
  version      = {1.0.0},
  doi          = {10.5281/zenodo.22748601},
  url          = {https://doi.org/10.5281/zenodo.22748601}
}

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Building-unit deconstruction, topology and porosity come from mofstructure, by the same author. Where those results matter to your conclusions, cite it as well - and cite Zeo++ if you report pore geometry, and RDKit if you report cheminformatic identifiers.

How the calculations compare with measured data and with published reference calculations, with the scripts that reproduce each number, is on the Validation page.

Report the topology method alongside any RCSR symbol. The deconstruction method changes the answer for frameworks with rod-shaped building units, and a symbol quoted without one is ambiguous - see the guide.

Contact