manypw.x: 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 CentOS possible default full paths are:

/usr/bin/manypw.x - from package: quantum-espresso

You may install the required package with command yum install {package}

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