mpispawn: 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/mvapich2-psm/bin/mpispawn - from package: mvapich2-psm
/usr/lib64/mvapich2/bin/mpispawn - from package: mvapich2
/usr/lib/mvapich2/bin/mpispawn - from package: mvapich2
/usr/lib64/mvapich-psm/bin/mpispawn - from package: mvapich-psm
/usr/lib64/mvapich/bin/mpispawn - from package: mvapich
/usr/lib/mvapich/bin/mpispawn - from package: mvapich

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

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