> For the complete documentation index, see [llms.txt](https://docs.materialsproject.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.materialsproject.org/apps/explorer-apps/mof-explorer/property-definitions/smiles-mofid-and-mofkey.md).

# SMILES, MOFid, and MOFkey

In prior work by [Bucior et al.](https://doi.org/10.1021/acs.cgd.9b01050), a pair of methods known as MOFid and MOFkey are described that can be used to assign a unique name for a given MOF. MOFid works by deconstructing a MOF into its node(s), linker(s), and topology. The nodes and linkers are represented as SMILES strings, the topology is determined using [Systre](http://gavrog.org), and any catenation is noted. These factors are combined into a single unique "MOFid". The MOFkey is simply a shorter, InChI-based hash of the MOFid. These methods are shown below for HKUST-1 (also known as Cu3(btc)2 and Cu-BTC):

![Example MOFid and MOFkey for the MOF with common name HKUST-1.](https://snurr-group.github.io/web-mofid/mofid.png)

The MOFid code is available [here](https://github.com/snurr-group/mofid) with a web-based version available [here](https://snurr-group.github.io/web-mofid).

The SMILES search on the MOF Explorer is a partial-match of the MOFid. As such, one can query by just the node, just the linker, or even a substructure of the linker. If the user wishes to supply both a node and linker query, they should be provided in the MOFid format (separated by a "." with the node(s) listed before the linker(s)).


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.materialsproject.org/apps/explorer-apps/mof-explorer/property-definitions/smiles-mofid-and-mofkey.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.