Cause: VMD does not know read carbondot.tcl
Solution:
1) Check, whether you really have all the files required for carbon dots in your nanotube1.5 folder – this includes not only carbondot.tcl, but also gui.tcl a pkgIndex.tcl.
2) Source carbondot.tcl manually – open TkConsole a type „source /path/to/carbondot/carbondot.tcl“)
In case of found bugs or problems with usage, please contact us (marketa.paloncyova@gmail.com) and we will try to solve the issue as soon as possible.