New install procedure & MPI interconnect in Ver. 6.0

We have been using Materials Studio (CASTEP, and later ONETEP too)  since Version 3.1  on  unsupported platforms, originally on a Debian cluster and currently on an Ubuntu cluster.   We are currently running Version 5.5.

While trying to figure out the new 6.0 install procedure I realized that HP-MPI is no longer used.  Before going further with the install I wanted to know if a site has to have Intel-MPI running or if there is a limited package included as part of the MS 6.0 distribution, as was HP-MPI  with previous releases.

Thanks,

Bob