mrgddb: 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/mrgddb - from package: abinit

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

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