Added doc/installations dir

doc/installations/theta.rst

+.. _theta:
+
+=================
+Theta-ALCF (XC40)
+=================
+
+Theta is a Cray XC40 located at Argonne National Laboratory. 
+
+.. code-block:: bash 
+
+   $ ssh -XY <username>@theta.alcf.anl.gov
+
+Building WEST
+~~~~~~~~~~~~~
+
+WEST executables can be compiled using the following script: 
+
+.. code-block:: bash 
+
+   $ cat build_theta.sh
+   #!/bin/bash
+
+   module load miniconda-3.6/conda-4.5.12
+
+   export BLAS_LIBS="-L$MKLROOT/intel64/lib -Wl,--start-group -lmkl_intel_lp64 -lmkl_core -lmkl_intel_thread -Wl,--end-group"
+   export SCALAPACK_LIBS="-L$MKLROOT/intel64/lib -Wl,--start-group -lmkl_scalapack_lp64 -lmkl_blacs_intelmpi_lp64 -lmkl_intel_lp64 -lmkl_core -lmkl_intel_thread -Wl,--end-group"
+   export FFT_LIBS=""
+   export MPIF90="ftn -g -mkl -dynamic"
+   export CC="cc -g -mkl -dynamic"
+   export F77="ftn -g -mkl -dynamic"
+   export FFLAGS="-xMIC-AVX512 -align array64byte -fp-model fast=2 -no-prec-div -assume byterecl -dynamic"
+   
+   export CRAYPE_LINK_TYPE=dynamic
+
+   ./install/configure --host=x86_64-build-linux-gnu --build=x86_64-target-linux-gnu --enable-parallel --with-scalapack --enable-openmp LD_LIBS="`python3-config --ldflags`"
+
+   make pw -j 16
+
+   cd West
+   make
+
+Running WEST Jobs
+~~~~~~~~~~~~~~~~~
+
+The following is an example executable script `run_west.sh` to run the `wstat.x` WEST executable on two nodes of Theta with 64 MPI ranks per node. The job can be submitted with command `qsub run_west.sh` where <project_name> is replaced with an active project allocation.
+
+.. code-block:: bash 
+
+   $ cat run_west.sh
+   #!/bin/bash
+   #COBALT -n 2 -t 10 -q debug-cache-quad -A <project_name> -O WEST
+   module load miniconda-3.6/conda-4.5.12 
+   aprun -n 128 -N 64 -d 1 --cc depth -e OMP_NUM_THREADS=1 -j 1 ./wstat.x -i wstat.in > wstat.out
+
+Job submission is done with the following: 
+
+.. code-block:: bash 
+
+   $ qsub run_west.sh
+
+.. seealso::
+   For more information, visit the ALCF user guide (`https://www.alcf.anl.gov/user-guides/xc40-system-overview <https://www.alcf.anl.gov/user-guides/xc40-system-overview/>`_).