scotch_dgord: 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/lib64/mpich/bin/scotch_dgord - from package: ptscotch-mpich
/usr/lib/mpich/bin/scotch_dgord - from package: ptscotch-mpich
/usr/lib64/openmpi/bin/scotch_dgord - from package: ptscotch-openmpi
/usr/lib/openmpi/bin/scotch_dgord - from package: ptscotch-openmpi

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