ptscotch_esmumps-long: 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 Debian possible default full paths are:

/usr/bin/ptscotch_esmumps-long - from package: ptscotch

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