TranMain_mpich: 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/mpich/bin/TranMain_mpich - from package: openmx-mpich

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

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