For those following the Skripal case, and the Russia-UK raw, here's a nice interview to one of the inventors of "Novichok", now living in the US.

He has published the complete formula in a book. But says only few governments in the world would have the capabilities to produce it.

https://www.novayagazeta.ru/articles/2018/03/15/75815-nado-bylo-navsegda-lishit-rossiyu-ee-sekreta