esysparticle: 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 Debian possible default full paths are:

/usr/bin/esysparticle - from package: esys-particle

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

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