No, assert(0) is correct: the total energy of a quake varies as the 3/2 power of the seismic moment. Both the Richter and Moment magnitude scales are based around the base-10 logarithm of the seismic moment, but that isn't the same as the total released energy of the quake.
By the way, I noticed that this fact is mentioned in the second paragraph of the very link that you cited. Did you perhaps stop reading after the first?
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