Then as I mentioned before, just type:
source ~/.bashrcThen all 3DNA v2.3 commands will be available directly. I've tried hard to help you avoid this 'extra' step. For now, it's better that you just remember to run this command.
For new users who has little background on command-line programs, the
w3DNA web server may be a better choice.
Thanks for your patience.
Xiang-Jun