You can easily look up the publication record of Massoud Ali-Mohammadi online, where you will find that his main work was in conformal field theory and later in general relativity. Both of these areas are quite far removed from any nuclear program Iran could be pursuing. Calling him a 'nuclear scientist' is very misleading.
U.K. is offering 4,000 resettlement spaces for Syrian refugees, UNHCR spokeswoman says (Reuters)
from the article: Ahmadinejad: Nuclear scientist assassinated in 'Zionist style'