mrgscr: 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/mrgscr - from package: abinit

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

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