diff --git a/blueprints/test_chemistry/config.bash b/blueprints/test_chemistry/config.bash
index 44ec3632155efccae34fdbe8cacbb2377c684e7c..618c66702703c3cad31329bd42371988d9d06ddc 100644
--- a/blueprints/test_chemistry/config.bash
+++ b/blueprints/test_chemistry/config.bash
@@ -100,8 +100,4 @@ TUVDataPath="/alcc/gpfs2/home/mbees/data/tuv/TUV.phot.bz2"
 
 # --- overriding default values ---
 
-nNodesMain=1
-nTasksPerNodeMain=9
-
-nNodesSpinup=1
-nTasksPerNodeSpinup=9
+nTasks=9
diff --git a/machine_profiles/alcc_spack/batch_preambles/main b/machine_profiles/alcc_spack/batch_preambles/main
index 51d7947ad0b4c2d6af97e3f29547ca9f8107c24e..b0189e750df24b7c1137efc216cdc1279ff1bc79 100644
--- a/machine_profiles/alcc_spack/batch_preambles/main
+++ b/machine_profiles/alcc_spack/batch_preambles/main
@@ -3,8 +3,7 @@
 #SBATCH -o __runDir__/__mainJobName__.%j.%N.out
 #SBATCH -D __runDir__
 #SBATCH -J __mainJobName__
-#SBATCH --nodes=__nNodesMain__
-#SBATCH --ntasks-per-node=__nTasksPerNodeMain__
+#SBATCH --ntasks=__nTasksMain__
 #SBATCH --mem-per-cpu=2200
 #SBATCH --mail-type=FAIL
 #SBATCH --mail-user=christoph.knote@med.uni-augsburg.de
diff --git a/machine_profiles/alcc_spack/batch_preambles/spinup b/machine_profiles/alcc_spack/batch_preambles/spinup
index 5693ae62c3f65ddba26a664a5e1c3711a99fad4d..c44982624ba3f05bc831abcd8feb36ae83bd940d 100644
--- a/machine_profiles/alcc_spack/batch_preambles/spinup
+++ b/machine_profiles/alcc_spack/batch_preambles/spinup
@@ -3,8 +3,7 @@
 #SBATCH -o __runDir__/__spinupJobName__.%j.%N.out
 #SBATCH -D __runDir__
 #SBATCH -J __spinupJobName__
-#SBATCH --nodes=__nNodesSpinup__
-#SBATCH --ntasks-per-node=__nTasksPerNodeSpinup__
+#SBATCH --ntasks=__nTask__
 #SBATCH --mem-per-cpu=2200
 #SBATCH --mail-type=FAIL
 #SBATCH --mail-user=christoph.knote@med.uni-augsburg.de
diff --git a/machine_profiles/alcc_spack/profile.bash b/machine_profiles/alcc_spack/profile.bash
index 56214414f772f31b01bd67b6d239d3e74ee84b9d..99a8bac52593a9a3c97f7079d66c541613a4af2e 100644
--- a/machine_profiles/alcc_spack/profile.bash
+++ b/machine_profiles/alcc_spack/profile.bash
@@ -4,21 +4,13 @@ module load wrf wrf-chem wps nco netcdf-c netcdf-fortran anthro_emis fire_emis m
 
 ulimit -s unlimited
 
-export OMPI_MCA_PML=ucx
-export UCX_TLS=tcp,sm
-export UCX_NET_DEVICES=eth5
-
 # --- MPI settings ---
 
-mpiCommandPre="mpirun"
+mpiCommandPre="mpirun -mca pml ucx -mca coll ^hcoll -x UCX_TLS=tcp,shm -x UCX_NET_DEVICES=eth5"
 mpiCommandMain="mpirun -mca pml ucx -mca coll ^hcoll -x UCX_TLS=tcp,shm -x UCX_NET_DEVICES=eth5"
 mpiCommandReal=${mpiCommandPre}
 
-nNodesMain=1
-nTasksPerNodeMain=64
-
-nNodesSpinup=1
-nTasksPerNodeSpinup=64
+nTasks=64
 
 # --- Batch system ---
 
diff --git a/master.bash b/master.bash
index 3fd791f47a2a87f98895b22f2f9918311887afd7..4a4a74c99a11b9a1d05f8bb22184c06dda2043b7 100755
--- a/master.bash
+++ b/master.bash
@@ -267,10 +267,7 @@ s/__refDateTxt__/${dateTxt}/g
 s/__domains__/${max_dom}/g
 s/__removeRunDir__/${removeRunDir}/g
 s/__metIncSec__/${metIncSec}/g
-s/__nNodesMain__/${nNodesMain}/g
-s/__nTasksPerNodeMain__/${nTasksPerNodeMain}/g
-s/__nNodesSpinup__/${nNodesSpinup}/g
-s/__nTasksPerNodeSpinup__/${nTasksPerNodeSpinup}/g
+s/__nTasks__/${nTasks}/g
 EOF
 
 # real run from -spinup to +fcstTime