ompi-clean: 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/ompi-clean - from package: openmpi-bin

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

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