I'm curious, given the stated figures (total thrust, rocket dimensions, payload to certain orbits), is it possible to calculate the specific impulse of this new

I'm curious, given the stated figures (total thrust, rocket dimensions, payload to certain orbits), is it possible to calculate the specific impulse of this new engine (with the atmo nozzles, I suppose)? I couldn't find it on their page, and I'm not quite well-enough versed in rocketry to even know if there's sufficient information to figure it out.