IQmol: 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 CentOS possible default full paths are:

/usr/bin/IQmol - from package: IQmol

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

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