# Retrieving compounds of garnet structure

I’m a new user and I just started to understand the materials project.
I used the tag function on the web page to retrieve the garnet structure, and only 98 structures were marked.
Can I obtain the garnet structure by searching for the chemical formula of A3B2C3O12?
How can I do it if I can?

Hi,

Welcome to the Materials Project! Indeed, wildcards are a supported feature of the Materials Explorer. You can search for

*3*2*3O12

to get all A3B2C3O12 compounds.

Best regards,
John D.

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It’s useful. Thanks a lot!
But I found another problem after searching in this way.
When I search some wildcards, it will show The most stable 500 results of all.
Can I get all the results?
Thanks again！

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You can, but I believe you’ll need to use our API for that use case. Here is some information and we’re always happy to help answer questions about the API on our forums. https://wiki.materialsproject.org/The_Materials_API

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Thank you so much!

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As well as formula, you can also search for the space group of garnet, e.g.

Or restrict it to space group plus Si and O:

This may be more or less useful depending on your application, since many garnet-derived structures might not have this exact space group.

Thank you very much！
I retrieved more results using the method you said.
But does the method you say mean that the compound with space group Ia3d must be a garnet structure?
After exporting the excel file, I found that there is no information about the ionic radius.
I wonder that how I can get the ionic radius information in the retrieved compound.
Thanks again!

No, there will be many Ia\bar{3}d structures that aren’t garnet, depending on how you define a “garnet” or “garnet-derived” structure, but it’s a useful way to narrow your search.

Ionic radii are available via the pymatgen code that we use, but you’d have to know the oxidation states of the elements present, you can also use pymatgen to guess what oxidation states are present but there’s no substitute to doing this manually. There are also tables of ionic radii available elsewhere online.

The problem is clear now.
You can use pymatgen’s MPRester.query() method. This uses the same syntax as MongoDB, and you can use it to query any fields in the mapidoc. This is advanced usage so is perhaps not as well documented as it should be.