Display/Building Data/Mass Data/Diaphragm Mass Data - This are the ones from the mass source, you have to multiply the mass for the gravity.
Display/Building Data/Materials/Material list by story - you get the masses from each stories
Why the weight used in the seismic calculation of lateral loads differ from the weight calculated from the supports reactions if I am taking into account the same mass source? I have a difference from 2557.09 t to 2453.81 t.