diff --git a/configs/sites/tier1/atlantis/packages.yaml b/configs/sites/tier1/atlantis/packages.yaml
index 0487117dd..0fb097d39 100644
--- a/configs/sites/tier1/atlantis/packages.yaml
+++ b/configs/sites/tier1/atlantis/packages.yaml
@@ -122,10 +122,11 @@ packages:
     externals:
     - spec: flex@2.6.1+lex
       prefix: /usr
-  openssl:
-    externals:
-    - spec: openssl@1.1.1k
-      prefix: /usr
+  # Can no longer use, issues with py-cryptography
+  #openssl:
+  #  externals:
+  #  - spec: openssl@1.1.1k
+  #    prefix: /usr
   gawk:
     externals:
     - spec: gawk@4.2.1
diff --git a/configs/sites/tier1/narwhal/compilers.yaml b/configs/sites/tier1/narwhal/compilers.yaml
index 22ddd17b4..eb74a5993 100644
--- a/configs/sites/tier1/narwhal/compilers.yaml
+++ b/configs/sites/tier1/narwhal/compilers.yaml
@@ -14,27 +14,30 @@ compilers::
       modules:
       - PrgEnv-intel/8.3.3
       - intel-classic/2023.2.0
+      - cray-libsci/23.05.1.4
       - libfabric/1.12.1.2.2.1
       environment:
         prepend_path:
           PATH: '/opt/cray/pe/gcc/10.3.0/snos/bin'
           CPATH: '/opt/cray/pe/gcc/10.3.0/snos/include'
-          LD_LIBRARY_PATH: '/opt/cray/libfabric/1.12.1.2.2.1/lib64:/opt/cray/pe/libsci/22.11.1.2/INTEL/19.0/x86_64/lib:/opt/cray/pe/gcc/10.3.0/snos/lib:/opt/cray/pe/gcc/10.3.0/snos/lib64'
+          LD_LIBRARY_PATH: '/opt/cray/libfabric/1.12.1.2.2.1/lib64:/opt/cray/pe/libsci/23.05.1.4/INTEL/2022.2/x86_64/lib:/opt/cray/pe/gcc/10.3.0/snos/lib:/opt/cray/pe/gcc/10.3.0/snos/lib64'
         set:
           CRAYPE_LINK_TYPE: 'dynamic'
       extra_rpaths: []
   - compiler:
       spec: gcc@10.3.0
       paths:
-        cc: cc
-        cxx: CC
-        f77: ftn
-        fc: ftn
+        cc: /opt/cray/pe/gcc/10.3.0/bin/gcc
+        cxx: /opt/cray/pe/gcc/10.3.0/bin/g++
+        f77: /opt/cray/pe/gcc/10.3.0/bin/gfortran
+        fc: /opt/cray/pe/gcc/10.3.0/bin/gfortran
       flags: {}
       operating_system: sles15
       modules:
       - PrgEnv-gnu/8.3.3
       - gcc/10.3.0
+      - cray-libsci/22.11.1.2
+      - libfabric/1.12.1.2.2.1
       environment:
         prepend_path:
           LD_LIBRARY_PATH: '/opt/cray/libfabric/1.12.1.2.2.1/lib64:/opt/cray/pe/libsci/22.11.1.2/GNU/9.1/x86_64/lib'
diff --git a/configs/sites/tier1/narwhal/packages_gcc.yaml b/configs/sites/tier1/narwhal/packages_gcc.yaml
index 3261960c6..0cc712415 100644
--- a/configs/sites/tier1/narwhal/packages_gcc.yaml
+++ b/configs/sites/tier1/narwhal/packages_gcc.yaml
@@ -7,7 +7,7 @@ packages:
     buildable: False
   cray-mpich:
     externals:
-    - spec: cray-mpich@8.1.21%gcc@10.3.0 ~wrappers
+    - spec: cray-mpich@8.1.21%gcc@10.3.0 +wrappers
       modules:
       - cray-mpich-ucx/8.1.21
       - craype-network-ucx
diff --git a/configs/sites/tier1/nautilus/packages_gcc.yaml b/configs/sites/tier1/nautilus/packages_gcc.yaml
index 08bb02aa5..841ff05b1 100644
--- a/configs/sites/tier1/nautilus/packages_gcc.yaml
+++ b/configs/sites/tier1/nautilus/packages_gcc.yaml
@@ -1,8 +1,17 @@
 packages:
+# On Nautilus, use intel-oneapi-mkl as provider
+# for blas, lapack, fftw-api with GNU because of
+# problems using openblas in downstream applications
+# (e.g. py-pandas):
+# ELF load command address/offset not properly aligned" when loading libopenblas.so
+# https://github.com/OpenMathLib/OpenBLAS/wiki/Faq#ELFoffset
   all:
     compiler:: [gcc@12.2.1]
     providers:
       mpi:: [openmpi@5.0.1]
+      blas:: [intel-oneapi-mkl]
+      fftw-api:: [intel-oneapi-mkl]
+      lapack:: [intel-oneapi-mkl]
   mpi:
     buildable: False
   openmpi:
@@ -12,3 +21,14 @@ packages:
       modules:
       - penguin/openmpi/5.0.1/gcc-8.5.0
       - slurm
+  openblas:
+    buildable: False
+  ectrans:
+    require::
+    - '@1.2.0 +mkl ~fftw'
+  gsibec:
+    require::
+    - '@1.2.1 +mkl'
+  py-numpy:
+    require::
+    - '@:1.25 ^intel-oneapi-mkl'
diff --git a/doc/source/PreConfiguredSites.rst b/doc/source/PreConfiguredSites.rst
index 4084281e0..b80cd7164 100644
--- a/doc/source/PreConfiguredSites.rst
+++ b/doc/source/PreConfiguredSites.rst
@@ -253,8 +253,12 @@ With Intel, the following is required for building new spack environments and fo
    module unload intel
    module load intel-classic/2023.2.0
    module unload cray-mpich
-   module load cray-mpich/8.1.21
+   module unload craype-network-ofi
+   module load craype-network-ucx
+   module load cray-mpich-ucx/8.1.21
    module load libfabric/1.12.1.2.2.1
+   module unload cray-libsci
+   module load cray-libsci/23.05.1.4
 
 THIS SECTION IS OUT OF DATE, REFER TO 1.7.0 RELEASE DOCUMENTATION -  - For ``spack-stack-1.7.0`` with Intel, proceed with loading the following modules:
 
@@ -279,8 +283,12 @@ With GNU, the following is required for building new spack environments and for
    module unload gcc
    module load gcc/10.3.0
    module unload cray-mpich
-   module load cray-mpich/8.1.21
+   module unload craype-network-ofi
+   module load craype-network-ucx
+   module load cray-mpich-ucx/8.1.21
    module load libfabric/1.12.1.2.2.1
+   module unload cray-libsci
+   module load cray-libsci/22.11.1.2
 
 THIS SECTION IS OUT OF DATE, REFER TO 1.7.0 RELEASE DOCUMENTATION - For ``spack-stack-1.7.0`` with GNU, proceed with loading the following modules: