gpaw-runscript: 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-runscript - from package: gpaw

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