ompi-iof: command not found

Have You tried accessing the binary with the full path?

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-iof - from package: openmpi-bin

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