OpticalConductivityMain_openmpi: 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/lib64/openmpi/bin/OpticalConductivityMain_openmpi - from package: openmx-openmpi

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

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