diff --git a/env/merlin/spack.yaml b/env/merlin/spack.yaml
index 4a3db2c..939c7ad 100644
--- a/env/merlin/spack.yaml
+++ b/env/merlin/spack.yaml
@@ -2,159 +2,159 @@ spack:
   concretizer:
     unify: false
   definitions:
-  - Compilers:
-    - '%clang@12.0.0'
-    - '%dpcpp@2022.1.0'
-    - '%gcc@12.1.0'
-    - '%intel@2021.6.0'
-    - '%nvhpc@21.5'
-    - '%oneapi@2022.1.0'
+    - Compilers: &Compilers
+      - '%clang@12.0.0'
+      - '%dpcpp@2022.1.0'
+      - '%gcc@12.1.0'
+      - '%intel@2021.6.0'
+      - '%nvhpc@21.5'
+      - '%oneapi@2022.1.0'
     # Careful!! Any external packages shouldn't be placed here, otherwise there is a possibility
     # they'll end with a module pointing to empty paths!!
-  - Batchsystem_pckgs:
-    - slurm
-  - Compiler_pckgs:
-    - atlas
-    - boost
-    - clapack
-    - clhep
-    - eigen
-    - geant4
-    - googletest
-    - gsl
-    - intel-oneapi-mpi
-    - kokkos
-    - libint tune=cp2k-lmax-6
-    - libxc
-    - libxsmm
-    - mpich
-    - openblas threads=none
-    - openblas threads=openmp
-    - openmpi
-    - root
-    - superlu
-    - vtk
-  - Cuda_pckgs:
-    - cuda
-  - EM_pckgs:
-    - cistem
-    - ctffind
-    - motioncor2
-    - relion
-    - unblur
-  - Librairies_pckgs:
-    - alsa-lib
-    - gdrcopy
-    - giflib
-    - gmp
-    - hwloc
-    - isl
-    - knem
-    - libtasn1
-    - mpc
-    - mpfr
-    - nettle
-    - pmix
-    - ucx
-    - udunits
-    - wxwidgets
-    - x264
-    - zlib
-  - MX_pckgs:
-    - cbflib
-    - lz4
-    - openbabel
-    - visit
-  - HDF5_pckgs:
-    - alps
-    - h5hut+mpi
-    - hdf5-blosc
-    - ioapi
-    - hdf5+mpi
-    - netcdf-c
-    - netcdf-fortran
-    - netcdf-c +parallel-netcdf
-    - trilinos
-  - HDF5_serial_pckgs:
-    - hdf5~mpi
-    - h5hut~mpi
-    - ncview
-  - MPI_pckgs:
-    - amrex
-    - boxlib
-    - cp2k
-    - cpmd
-    - elegant
-    - elpa
-    - fftw
-    - gromacs
-    - lammps
-    - astra
-  - Programming_pckgs:
-    - autoconf
-    - automake
-    - binutils
-    - bison
-    - cmake
-    - erlang
-    - gcc
-    - go
-    - intel
-    - openjdk
-    - julia
-    - libtool
-    - lua
-    - m4
-    - nasm
-    - perl
-    - nvhpc
-    - python
-    - py-tensorflow
-    - qt
-    - r
-    - tcl
-    - tk
-  - System_pckgs:
-    - bash
-    - filebench
-    - ior
-    - mdtest
-    - nmap
-    - patchelf
-    - unison
-  - Tools_pckgs:
-    - aria2
-    - asciidoc
-    - coreutils
-    - emacs
-    - ffmpeg
-    - gaussian
-    - gettext
-    - git
-    - global
-    - gnupg
-    - gnuplot
-    - gnutls
-    - hdfview
-    - krb5
-    - kubernetes
-    - namd
-    - ncview
-    - openjpeg
-    - openssl
-    - orca
-    - paraview
-    - texlive
-    - tmux
-    - uncrustify
-    - vim
-    - visit
-    - xmlto
-    - xz
+    - Batchsystem_pckgs: &Batchsystem_pckgs
+        - slurm
+    - Compiler_pckgs: &Compiler_pckgs
+        - atlas
+        - boost
+        - clapack
+        - clhep
+        - eigen
+        - geant4
+        - googletest
+        - gsl
+        - intel-oneapi-mpi
+        - kokkos
+        - libint tune=cp2k-lmax-6
+        - libxc
+        - libxsmm
+        - mpich
+        - openblas threads=none
+        - openblas threads=openmp
+        - openmpi
+        - root
+        - superlu
+        - vtk
+    - Cuda_pckgs: &Cuda_pckgs
+        - cuda
+    - EM_pckgs: &EM_pckgs
+        - cistem
+        - ctffind
+        - motioncor2
+        - relion
+        - unblur
+    - Librairies_pckgs: &Librairies_pckgs
+        - alsa-lib
+        - gdrcopy
+        - giflib
+        - gmp
+        - hwloc
+        - isl
+        - knem
+        - libtasn1
+        - mpc
+        - mpfr
+        - nettle
+        - pmix
+        - ucx
+        - udunits
+        - wxwidgets
+        - x264
+        - zlib
+    - MX_pckgs: &MX_pckgs
+        - cbflib
+        - lz4
+        - openbabel
+        - visit
+    - HDF5_pckgs: &HDF5_pckgs
+        - alps
+        - h5hut+mpi
+        - hdf5-blosc
+        - ioapi
+        - hdf5+mpi
+        - netcdf-c
+        - netcdf-fortran
+        - netcdf-c +parallel-netcdf
+        - trilinos
+    - HDF5_serial_pckgs: &HDF5_serial_pckgs
+        - hdf5~mpi
+        - h5hut~mpi
+        - ncview
+    - MPI_pckgs: &MPI_pckgs
+        - amrex
+        - boxlib
+        - cp2k
+        - cpmd
+        - elegant
+        - elpa
+        - fftw
+        - gromacs
+        - lammps
+        - astra
+    - Programming_pckgs: &Programming_pckgs
+        - autoconf
+        - automake
+        - binutils
+        - bison
+        - cmake
+        - erlang
+        - gcc
+        - go
+        - intel
+        - openjdk
+        - julia
+        - libtool
+        - lua
+        - m4
+        - nasm
+        - perl
+        - nvhpc
+        - python
+        - py-tensorflow
+        - qt
+        - r
+        - tcl
+        - tk
+    - System_pckgs: &System_pckgs
+        - bash
+        - filebench
+        - ior
+        - mdtest
+        - nmap
+        - patchelf
+        - unison
+    - Tools_pckgs: &Tools_pckgs
+        - aria2
+        - asciidoc
+        - coreutils
+        - emacs
+        - ffmpeg
+        - gaussian
+        - gettext
+        - git
+        - global
+        - gnupg
+        - gnuplot
+        - gnutls
+        - hdfview
+        - krb5
+        - kubernetes
+        - namd
+        - ncview
+        - openjpeg
+        - openssl
+        - orca
+        - paraview
+        - texlive
+        - tmux
+        - uncrustify
+        - vim
+        - visit
+        - xmlto
+        - xz
   include:
-  - sysconfigs/config.yaml
-  - sysconfigs/compilers.yaml
-  - sysconfigs/packages.yaml
+    - sysconfigs/config.yaml
+    - sysconfigs/compilers.yaml
+    - sysconfigs/packages.yaml
 #>>> modules.yaml
   modules:
     Batchsystem:
@@ -545,18 +545,18 @@ spack:
 #<<<
   specs:
     - matrix: 
-      - [cmake,cuda,fftw,gromacs,kokkos,mpich netmod=ucx,nvhpc+mpi,openblas threads=none,openblas threads=openmp,
+      - [cmake,cuda,fftw,gromacs,kokkos,mpich netmod=ucx,nvhpc,openblas threads=none,openblas threads=openmp,
          python,root~tbb~x,slurm,gsl]
       - ['%gcc']
     - matrix:
-      - [boost]
+      - [boost, hdf5~mpi, openmpi]
       - ['%clang','%gcc','%nvhpc','%oneapi']
-    - matrix:
-      - [hdf5~mpi, openmpi]
-      - ['%gcc','%oneapi']
+      exclude:
+      - hdf5~mpi%clang
+      - openmpi%clang
     - matrix:
       - [hdf5+mpi +fortran +hl +shared, netcdf-fortran, netcdf-c +parallel-netcdf]
-      - ['%gcc','%oneapi']
+      - ['%gcc','%nvhpc','%oneapi']
       - [^openmpi]
     - intel-oneapi-mpi%oneapi
   view: