mpicc.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 Debian possible default full paths are:

/usr/bin/mpicc.mpich - from package: libmpich-dev

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

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