hp_calc_powspec: 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/hp_calc_powspec - from package: healpix-c++

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