How to choose the snapshot from the trajectory in MD simulation?

Dear Hiphive teams,

I try to run the MD and got the traj files, then I want to choose some of snapshots from the trajectory as training structures to improve the stability of FCP, but I don't know how to choose the snapshots, Would you have any suggestions?

The number of original training stuctures is 15 from MC-rattle and using lasso fitting method to get the first FCP.

trajs_T300.trajlogs_T300

Another problem is the post-processing of MD simulation, in the paper of 'efficient construction and applications of higher-order force constant models', I saw the figures of the density of states and SED of Ba8Ga16Ge30 at finite temperature, but I don't know how to redo these results? maybe there are some other analysis software to help me? at least for ASE, I cannot find the method to get the dos and SED at finite temperature.

Edited by Francis