# Page Not Found

The URL `files/t2eQJKjlUpTAOXBiN4kN` does not exist. This page may have been moved, renamed, or deleted.

## Suggested Pages

You may be looking for one of the following:
- [Tutorial](https://simplemetalens.gitbook.io/docs/smd-pro/tutorial.md)
- [2.2. Imaging](https://simplemetalens.gitbook.io/docs/smd-pro/tutorial/basic-workflow/2.-simulate/2.2.-imaging.md)
- [Lens Equation (Gaussian formula)](https://simplemetalens.gitbook.io/docs/smd-pro/topical-discussions/lens-equation.md)
- [Unit Cell Position Numbers (UPNs)](https://simplemetalens.gitbook.io/docs/smd-pro/topical-discussions/unit-cell-position-numbers-upns.md)
- [Aberrations](https://simplemetalens.gitbook.io/docs/smd-pro/topical-discussions/aberrations.md)

## How to find the correct page

If the exact page cannot be found, you can still retrieve the information using the documentation query interface.

### Option 1 — Ask a question (recommended)

Perform an HTTP GET request on the documentation index with the `ask` parameter:

```
GET https://simplemetalens.gitbook.io/docs/smd-pro/tutorial.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.

### Option 2 — Browse the documentation index

Full index: https://simplemetalens.gitbook.io/docs/sitemap.md

Use this to discover valid page paths or navigate the documentation structure.

### Option 3 — Retrieve the full documentation corpus

Full export: https://simplemetalens.gitbook.io/docs/llms-full.txt

Use this to access all content at once and perform your own parsing or retrieval. It will be more expensive.

## Tips for requesting documentation

Prefer `.md` URLs for structured content, append `.md` to URLs (e.g., `/docs/smd-pro/tutorial.md`).

You may also use `Accept: text/markdown` header for content negotiation.