Number of     in System A   System B       Total U:   ε      

Show (up to) 100 "bins" of     macropartitions  

UA / ε UB / ε UA / U UB / U ΩA ΩB ΩAB Probability
 Plot logarithm

       Value of UA at peak: 0.500 U

       Half-max width: 0.6667 U

StatMech (this app) creates macropartition tables for Einstein solids in thermal contact. See Chapter T2 of Unit T of the Six Ideas That Shaped Physics text for examples of such tables and a description of this application. This new version uses a much faster algorithm and handles total energies of up to a million fundamental units ε. It also calculates peak widths more accurately.

Note that when the total energy exceeds 100ε, the application automatically groups macropartitions into bins so that there are never more than 101 rows in the table. You may reduce the number of macropartitions in a bin from what the application first suggests, but you will always be limited to 100 table rows, meaning that your table may span only a subset of possibilities. Note that with large systems, choosing a subset not centered on the peak may show nothing on the graph, because there is nothing to show except an essentially vertical spike at the right or left edge. Plotting the logarithm will more clearly show what is going on in such a case.

This Javascript app was written by Thomas Moore (Pomona College). The plots are drawn using the open-source Plotly.js library. Please report bugs to the author via the Six Ideas website.