Does MP have listings for experimental bandgaps along with the calculated ones?

I’m trying to compare DFT bandgaps with experimental data. However, I’m having problems finding information on experimental bandgaps. The papers I’ve looked at just say: taken from “literature.” I know that MP provides references for some materials and has an entry for “theoretical.” Does MP have a specific entry for experimentally observed bandgap?

Hi @Nikolai_Simonov,

We do not currently list experimental references, however there are several datasets available. In particular, I would recommend this one: MPContribs (more details available at Table of Datasets — matminer 0.7.8 documentation).

However, take these experimental datasets with caution. While many experimental references are high-quality, having assembled some of these myself in the past, I’ve noticed some materials with wildly varying reported gaps (of > 1 eV in some cases!). This can be for many reasons: differing sample quality or sample preparation, different characterization methods, measurement of direct vs indirect/fundamental gap, optical vs electronic gap (e.g. there may be forbidden transitions present), mis-reporting of symmetry or polymorph or error in transcription/digitization (especially for older papers), the list goes on.

In other words, I would recommend referring to these datasets with caution and always double-checking the original reference.

Hope this helps!

Matt

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