# Avo\_xtb plugin and periodic systems

**URL:** <https://discuss.avogadro.cc/t/avo-xtb-plugin-and-periodic-systems/6777>\
**Category:** Plugins\
**Created:** [February 18, 2025, 10:41pm UTC](https://discuss.avogadro.cc/t/avo-xtb-plugin-and-periodic-systems/6777 "2025-02-18T22:41:15Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Miroslav\_Ilias](https://discuss.avogadro.cc/user_avatar/discuss.avogadro.cc/miroslav_ilias/32/511_2.png) [@Miroslav\_Ilias](https://discuss.avogadro.cc/u/Miroslav_Ilias)\
**Post date:** [February 18, 2025, 10:41pm UTC](https://discuss.avogadro.cc/t/avo-xtb-plugin-and-periodic-systems/6777/1 "2025-02-18T22:41:15Z")

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Hello, dear experts !

the GFN-FF method is supporting periodic systems, see [Periodic boundary conditions for the GFN-FF · Issue #185 · grimme-lab/xtb · GitHub](https://github.com/grimme-lab/xtb/issues/185#issuecomment-2501191784) , also [Release xtb version 6.7.0 · grimme-lab/xtb · GitHub](https://github.com/grimme-lab/xtb/releases/tag/v6.7.0) new features.

How to integrate the periodicity into avo\_xtb plugin please ?

By default, avo\_xtb prepares the xyz input file for xtb without lattice parameters.

How to overcome that, please ? Avogadro2 has nice crystal builder.

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**Author:** ![matterhorn103](https://discuss.avogadro.cc/user_avatar/discuss.avogadro.cc/matterhorn103/32/1751_2.png) [@matterhorn103](https://discuss.avogadro.cc/u/matterhorn103)\
**Post date:** [February 19, 2025, 12:59am UTC](https://discuss.avogadro.cc/t/avo-xtb-plugin-and-periodic-systems/6777/2 "2025-02-19T00:59:54Z")

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The plugin doesn’t support periodic geometries at the moment I’m afraid. For now I’d suggest saving the geometry to file and launching `xtb` on the command line.

To allow for periodic structures I’d need to add code to the plugin to both read and write Turbomole-format files. It is on the to-do list, I just haven’t got round to it yet.

There’s an issue open for it [here](https://github.com/matterhorn103/avo_xtb/issues/70) which you are welcome to give a thumbs-up to and/or follow for any future changes.

I’ll also encourage anyone else who reads this in future to let me know if they’re keen to see it implemented, it’s hard to gauge popularity/demand.

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**Author:** ![ghutchis](https://discuss.avogadro.cc/user_avatar/discuss.avogadro.cc/ghutchis/32/456_2.png) [@ghutchis](https://discuss.avogadro.cc/u/ghutchis)\
**Post date:** [February 19, 2025, 1:28am UTC](https://discuss.avogadro.cc/t/avo-xtb-plugin-and-periodic-systems/6777/3 "2025-02-19T01:28:23Z")

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> [@matterhorn103](#):
>
> To allow for periodic structures I’d need to add code to the plugin to both read and write Turbomole-format files. It is on the to-do list, I just haven’t got round to it yet.

I know that some of the xtb developers looked at adding `cjson` support directly. I haven’t tried that, but it would presumably work for fractional coordinates too. But it’s one reason I added native Turbomole format support to Avogadro for handling `coord` files from xtb.

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**Author:** ![matterhorn103](https://discuss.avogadro.cc/user_avatar/discuss.avogadro.cc/matterhorn103/32/1751_2.png) [@matterhorn103](https://discuss.avogadro.cc/u/matterhorn103)\
**Post date:** [February 19, 2025, 3:30am UTC](https://discuss.avogadro.cc/t/avo-xtb-plugin-and-periodic-systems/6777/4 "2025-02-19T03:30:28Z")

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Sure, but the plugin now runs on the underlying `easyxtb` package, which I’d want to support `.coord` too, and `easyxtb` stores/provides/works with an internal representation of geometries to allow programmatic use.