fqha.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/fqha.x - from package: quantum-espresso

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

On Debian possible default full paths are:

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

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

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