Robert Palgrave Profile picture
Professor of Inorganic and Materials Chemistry at UCL. Director of UK National XPS Service @harwellxps
Nov 12, 2024 20 tweets 5 min read
A new paper about AI in Materials Discovery has gained a lot of attention - it reports a big increase in productivity of scientists using AI tools, and interesting secondary effects of using AI for science.

But do the technical claims stack up? Let's see... The paper can be found here



The sole author is Aidan Toner-Rodgers, who is a PhD student in Economics at MIT.aidantr.github.io/files/AI_innov…
Jan 8, 2024 11 tweets 3 min read
We have now completed our analysis of new materials reported in the Google Deepmind / Berkeley autonomous lab paper. My own initial analysis is in the quote tweet.

Happy to have worked with @SchoopLab to jointly put together a comprehensive analysis, now available on @ChemRxiv.

This thread is my personal view after having looked at the detail of each of the materials reported 🧵

chemrxiv.org/engage/chemrxi… The headline conclusions:

It is likely that no new materials were discovered.

Most of the materials produced were misidentified, and the rest were already known

This happened because of problems in both the computational and the experimental portions of the work.
Jan 5, 2024 13 tweets 4 min read
I've seen two posts on the Zhihu website that have more information on the synthesis of the new sulfur version of LK99, in the preprint by Wang et al.

Some more of the motivation for this synthesis is becoming clearer, and some pretty interesting points emerge..... First the posts on Zhihu:

Post 1

Post 2

I read these via Google translate with some help from native speakers. But certainly I may be getting things wrong due to language.zhuanlan.zhihu.com/p/673082514?ut…
zhuanlan.zhihu.com/p/676103064?ut…
Jan 4, 2024 16 tweets 5 min read
A new preprint on LK99 has caught some attention. Some solid state chemistry based thoughts....

arxiv.org/pdf/2401.00999…
Let's quickly recap the Summer '23 LK99 phenomenon. The compound was claimed to be copper doped lead apatite, or more specifically, Pb₉Cu(PO₄)₆O.

This was reported to be made in a very unusual synthesis form lead sulfate and copper phosphide.
Dec 2, 2023 15 tweets 4 min read
Thanks for you additional data and comments. I read both post on LinkedIn and will post below, probably copy to LinkedIn too.

Thank you for providing additional analysis of your M-Sb-Pb-O compounds. You initially published the M= In and Fe compounds as hexagonal crystal system, and the M= Zr, Hf and Sn as tetragonal.
You now appear to claim that all are in fact doped Sb2Pb2O7, which is cubic and has a different structure to any of those you published in your paper
Nov 30, 2023 15 tweets 5 min read
This exciting paper shows AI design of materials, robotic synthesis. 10s of new compounds in 17 days.

But did they?

This paper has very serious problems in materials characterisation. In my view it should never have got near publication. Hold on tight let's take a look 😱 The paper reports many 'new' compounds. The only characterisation they show is powder XRD. What no compositional analysis? Nope.

But maybe it's ok if they did a great job with the XRD analysis?

Oh. Image
Aug 3, 2023 12 tweets 3 min read
Latest replication attempt, and this one claims zero resistance. The paper is published as a video (obviously), link in Alex's thread, but here are my comments on the chemistry. 🧵 The authors use 4 different compositions. They replicate the reaction of the original Korean paper, with lanarkite + Cu3P, but also use a different lead precursor Pb3O2(SO4).

They also use 1:1 ratio of precursors and also a more Cu3P rich ratio
Jul 31, 2023 7 tweets 2 min read
The #LK99 patent reveals more about the chemistry of the new superconductor

The patent specifies a large range of compositions, far beyond the original papers. It also includes some analysis of the actual compositions of the material - some thoughts...🧵

patentimages.storage.googleapis.com/68/45/e1/a434f… We finally have some EDX measurements of composition- summarised below. Two sets of LK99 are measured (fig 28, 41) First thing to note is how oxygen and copper rich they are compared with theory (shown right)

Second is how far the reactants are from the stated LK99 composition Image
Jul 27, 2023 20 tweets 4 min read
There is a lot of excitement about a possible new room temperature superconductor.

A lot of physicists have weighed in on the superconducting results but I haven't seen much comment on the material itself and how they made it. So here's my take 🧵

I don’t know enough about the superconductivity. But I can talk about the chemistry and characterisation.

Short version: structural and chemical characterisation is poor, with fundamental mistakes and omissions, and the material may well be quite different to what is presented.