lhapdf-getdata: 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/lhapdf-getdata - from package: python-lhapdf

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

On Debian possible default full paths are:

/usr/bin/lhapdf-getdata - from package: python-lhapdf

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

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