rasmol-gtk: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/rasmol-gtk - from package: rasmol

You may install the required package with command apt-get install {package}

Error in other languages:
rasmol-gtk: bevel nie gevind nie
rasmol-gtk: comandă negăsită
rasmol-gtk: comando não encontrado
rasmol-gtk: commande introuvable
rasmol-gtk: command not found
rasmol-gtk: käsku ei ole
rasmol-gtk: không tìm thấy lệnh
rasmol-gtk: komanda nerasta
rasmol-gtk: Kommando nicht gefunden.
rasmol-gtk: kommandot finns inte
rasmol-gtk: komut yok
rasmol-gtk: nie znaleziono polecenia
rasmol-gtk: níor aimsíodh an t-ordú
rasmol-gtk: no se encontró la orden
rasmol-gtk: no s'ha trobat l'ordre
rasmol-gtk: opdracht niet gevonden
rasmol-gtk: parancs nem található
rasmol-gtk: perintah tidak ditemukan
rasmol-gtk: príkaz nenájdený
rasmol-gtk: příkaz nenalezen
rasmol-gtk: команда не найдена
rasmol-gtk: командата не е открита
rasmol-gtk: 命令找不到
rasmol-gtk: コマンドが見つかりません