obchiral: 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/obchiral - from package: openbabel

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

On Debian possible default full paths are:

/usr/bin/obchiral - from package: openbabel

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