BLACS and multiple MPI communicators

Dear all,

I am trying to use parallel version of ?heevr (i.e., p?heevr of SCALAPACK) to get eigenvalues. To do so, it seems that I need to initialize BLACS.

There are N cores in the system, which I divided into n subgroups with m cores each (N = n x m) by using MPI_Comm_split(). The matrices assigned to each subgroup are all different.

The question is that, is it possible to initialize BLACS in each subgroup independently? I am asking this because, although MPI can manage the cores by MPI communicators (MPI_COMM_WORLD for the entire N cores and extra communicators for each subgroup), I cannot find such 'tag' in BLACS.

Thank you in advance.

Pilkyung