Running NWChem with MPICH
-------------------------

tldr:
       set ARMCI_USE_WIN_ALLOCATE=0 when running nwchem.mpich


When nwchem.mpich is run over multiple processes, it may give an error
e.g. on 2 processes

 iter       energy          gnorm     gmax       time
             ----- ------------------- --------- --------- --------
                 1      -75.9473154351  8.06D-01  3.50D-01      0.2
  ga_iter_lsolve: convergence stagnant ... aborting solve
 Increased level shift to     2.00
  ga_iter_lsolve: convergence stagnant ... aborting solve


or on 3 processes

 Symmetry analysis of molecular orbitals - initial
      -------------------------------------------------

 sym_movecs_adapt: orbital    10 negative proj. 
   1.00D+00 -2.08D-05 -1.04D-05 -5.55D-17
 ------------------------------------------------------------------------
 sym_movecs_adapt: negative proj                   0
 ...
 For further details see manual section: No section for this category                                                                                                                                                                                                                                   
[0] ARMCI Error: 0:sym_movecs_adapt: negative proj:
Abort(-1) on node 0 (rank 0 in comm 496): application called MPI_Abort(comm=0x84000002, -1) - process 0


When this happens, the fix is to set the environment variable

  ARMCI_USE_WIN_ALLOCATE=0

For more discussion, see https://github.com/nwchemgit/nwchem/issues/633
