I am doing md simulation for protein aggregation. For doing cluster analysis I was trying with gmx clustsize. Now the plot that I am getting, can not find a proper explanation. With -hc flag the histogram I got cluster size vs frequency of observation. What does the cluster size means, what should be the unit of cluster size, is it nm? Also, I got a plot for average cluster over time, initially it is having a fluctuation, then it reached to a plateau then again there is fluctuation, here in the y axis is it the number of different conformations at a particular point?