Hiroshima had 1000 times more raw energy, plus, lots of it was penetrating radiation and thermal, not just blast. And even given that, got ~30% lethality within 3 miles.
I’m familiar with FAB and therbobaric physics. Even an enhanced thermobaric with a CL-20 core and ethylene oxide load won’t match that, at 11 tons TNT eq.
The Russian bomb is only a little bigger than our MOAB.
Sorry, they are making the lethality numbers up. Makes sense; you want your enemies to be frightened of your capabilities.
So, you want to compare the combustibles, not the energy release to determine lethality from suffocation in a given period of time, which is what? ~ something like 5 minutes maybe.
Buildings and human bodies are going to burn more slowly than gasoline. Keep that in mind as you do your comparisons.
Also, assume the Russians have improved on the performance of the device since our last announced attainments. We may also have improved the MOAB, but who's saying anything?