first of all I would like to thank you for your cooperation, I solve the problem, it's in the ext command line I just remove the additionnel "o" from "soource"
Best wishes.
I have sufficently illustrated all steps in the video tutorial, there is no hidden step(s).
I did everything you did in the video.
What do you suggest to me?
That means you didn't properly modify vmd.rc file and then reboot VMD, or the ESPext.vmd script provided in Multiwfn package has not been moved to default folder of VMD program, therefore the content of the script was not activated when VMD boots up.
I'm plotting ESP colored vdW surface with ESP extrema but it does not appear, when I set "ext" command i get the message "invalid command name "soource""