gpaw-setup: 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 CentOS possible default full paths are:

/usr/bin/gpaw-setup - from package: gpaw

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