Calculate and double MC steps a few times to accumulate a good histogram.
The right hand graph now plots the heat capacity of lead for the numerical simulation (in blue), the Debye model (in red), and the experimental data (the points). Be sure to switch to the log/log option in the axes menu to reveal what goes on at low T. Does the best choice of the velocity for the Debye model depend upon whether you use the linear or log/log plot?