diff --git a/env/rhel7/x86_64/admin/stable/spack.yaml b/env/rhel7/x86_64/admin/stable/spack.yaml
index 4648c5f..a40e24c 100644
--- a/env/rhel7/x86_64/admin/stable/spack.yaml
+++ b/env/rhel7/x86_64/admin/stable/spack.yaml
@@ -13,6 +13,5 @@ spack:
     - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
   mirrors:
     local_stable: file:///afs/psi.ch/software/spack/stable
-  specs:
-    - gcc@12.3.0
+  specs: []
   view: false
diff --git a/env/rhel7/x86_64/admin/testing/spack.yaml b/env/rhel7/x86_64/admin/testing/spack.yaml
index 8a8b800..fc09333 100644
--- a/env/rhel7/x86_64/admin/testing/spack.yaml
+++ b/env/rhel7/x86_64/admin/testing/spack.yaml
@@ -14,6 +14,5 @@ spack:
   mirrors:
     local_testing: file:///afs/psi.ch/software/spack/testing
     local_unstable: file:///afs/psi.ch/software/spack/unstable
-  specs:
-  - opal@master%gcc@12.3.0 ^openmpi
+  specs: []
   view: false
diff --git a/env/rhel7/x86_64/admin/unstable/spack.yaml b/env/rhel7/x86_64/admin/unstable/spack.yaml
index 26299f4..d9e8e16 100644
--- a/env/rhel7/x86_64/admin/unstable/spack.yaml
+++ b/env/rhel7/x86_64/admin/unstable/spack.yaml
@@ -14,5 +14,9 @@ spack:
   mirrors:
     local_unstable: file:///afs/psi.ch/software/spack/unstable
     local_stable: file:///afs/psi.ch/software/spack/stable
-  specs: []
+  specs:
+  - matrix:
+    - [cp2k@2024.1, opal@master]
+    - ['^openmpi']
+    - ['%gcc@12.3.0']
   view: false
diff --git a/env/rhel7/x86_64/sysconfigs/packages.yaml b/env/rhel7/x86_64/sysconfigs/packages.yaml
index 174b9f1..ed06eb8 100644
--- a/env/rhel7/x86_64/sysconfigs/packages.yaml
+++ b/env/rhel7/x86_64/sysconfigs/packages.yaml
@@ -5,7 +5,7 @@ packages:
     providers:
       blas: [openblas, nvhpc]
       lapack: [openblas, nvhpc]
-      mpi: [openmpi]
+      mpi: [openmpi, mpich, intel-oneapi-mpi]
       pkgconfig: [pkg-config]
     target: [x86_64]
     # Default GPU arch