
It's a rather inexact science, as you'll see in our paper.
And even better, the publishers have made the article freely available for the next month - so anyone can read it without a paid subscription (UPDATE: This free offer has now lapsed... sorry!)
Our thanks to Nature Chemistry.
Click here for the article online.
And click here to download as a PDF.
What a lovely treat as we prepare to upload our 300th film to The Periodic Table of Videos.