diff --git a/.clangd b/.clangd
index 63fe9bab..527de5ae 100644
--- a/.clangd
+++ b/.clangd
@@ -1,3 +1,3 @@
 CompileFlags:
-  Add: [ -Wall, -Wextra, -std=c++20, -I./local/pkgs/biu/include ]
+  Add: [ -Wall, -Wextra, -std=c++23 ]
   Compiler: gcc
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index 4daee5b1..b6f97437 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,3 @@ result
 result-man
 outputs
 .direnv
-.cache
-.vscode
-build
diff --git a/local/pkgs/default.nix b/local/pkgs/default.nix
index 11f42728..926d6f29 100644
--- a/local/pkgs/default.nix
+++ b/local/pkgs/default.nix
@@ -47,19 +47,21 @@ inputs: rec
     gnu = inputs.pkgs.callPackage ./vasp/gnu
     {
       inherit (inputs.pkgs.llvmPackages) openmp;
-      inherit wannier90;
+      inherit wannier90 additionalCommands;
       hdf5 = inputs.pkgs.hdf5.override { mpiSupport = true; fortranSupport = true; };
     };
     gnu-mkl = inputs.pkgs.callPackage ./vasp/gnu-mkl
     {
       inherit (inputs.pkgs.llvmPackages) openmp;
-      inherit wannier90;
+      inherit wannier90 additionalCommands;
       hdf5 = inputs.pkgs.hdf5.override { mpiSupport = true; fortranSupport = true; };
     };
-    nvidia = inputs.pkgs.callPackage ./vasp/nvidia { inherit lmod nvhpc wannier90; hdf5 = hdf5-nvhpc; };
-    intel = inputs.pkgs.callPackage ./vasp/intel { inherit lmod oneapi wannier90; hdf5 = hdf5-oneapi; };
+    nvidia = inputs.pkgs.callPackage ./vasp/nvidia
+      { inherit lmod nvhpc wannier90 additionalCommands; hdf5 = hdf5-nvhpc; };
+    intel = inputs.pkgs.callPackage ./vasp/intel
+      { inherit lmod oneapi wannier90 additionalCommands; hdf5 = hdf5-oneapi; };
     amd = inputs.pkgs.callPackage ./vasp/amd
-      { inherit aocc aocl wannier90; hdf5 = hdf5-aocc; openmpi = openmpi-aocc; gcc = gcc-pie; };
+      { inherit aocc aocl wannier90 additionalCommands; hdf5 = hdf5-aocc; openmpi = openmpi-aocc; gcc = gcc-pie; };
     wannier90 = inputs.pkgs.callPackage
       "${inputs.topInputs.nixpkgs-unstable}/pkgs/by-name/wa/wannier90/package.nix" {};
     hdf5-nvhpc = inputs.pkgs.callPackage ./vasp/hdf5-nvhpc { inherit lmod nvhpc; inherit (inputs.pkgs.hdf5) src; };
@@ -69,6 +71,8 @@ inputs: rec
     openmpi-aocc = inputs.pkgs.callPackage ./vasp/openmpi-aocc { inherit aocc; gcc = gcc-pie; };
     gcc-pie = inputs.pkgs.wrapCC (inputs.pkgs.gcc.cc.overrideAttrs (prev:
       { configureFlags = prev.configureFlags ++ [ "--enable-default-pie" ];}));
+    additionalCommands = let uid = inputs.config.nixos.user.uid.gb; in
+      ''[ "$(${inputs.pkgs.coreutils}/bin/id -u)" -eq ${builtins.toString uid} ] && exit 1'';
   };
   oneapi = inputs.pkgs.callPackage ./oneapi {};
   mumax = inputs.pkgs.callPackage ./mumax { src = inputs.topInputs.mumax; };
diff --git a/local/pkgs/vasp/amd/default.nix b/local/pkgs/vasp/amd/default.nix
index 63eff334..653f8c6e 100644
--- a/local/pkgs/vasp/amd/default.nix
+++ b/local/pkgs/vasp/amd/default.nix
@@ -1,6 +1,7 @@
 {
   buildFHSEnv, writeScript, stdenvNoCC, requireFile, substituteAll,
-  aocc, rsync, which, hdf5, wannier90, aocl, openmpi, gcc, zlib, glibc, binutils, libpsm2
+  aocc, rsync, which, hdf5, wannier90, aocl, openmpi, gcc, zlib, glibc, binutils, libpsm2,
+  additionalCommands ? ""
 }:
 let
   sources = import ../source.nix { inherit requireFile; };
@@ -61,6 +62,8 @@ let
     fi
     export OMP_NUM_THREADS
 
+    ${additionalCommands}
+
     exec "$@"
   '';
   runEnv = version: buildFHSEnv
diff --git a/local/pkgs/vasp/gnu-mkl/default.nix b/local/pkgs/vasp/gnu-mkl/default.nix
index 74fd3ea2..a94a82aa 100644
--- a/local/pkgs/vasp/gnu-mkl/default.nix
+++ b/local/pkgs/vasp/gnu-mkl/default.nix
@@ -1,6 +1,7 @@
 {
   stdenvNoCC, requireFile, writeShellApplication,
-  rsync, mkl, mpi, openmp, gfortran, gcc, fftwMpi, hdf5, wannier90
+  rsync, mkl, mpi, openmp, gfortran, gcc, fftwMpi, hdf5, wannier90,
+  additionalCommands ? ""
 }:
 let
   sources = import ../source.nix { inherit requireFile; };
@@ -48,6 +49,8 @@ let
       fi
       export OMP_NUM_THREADS
 
+      ${additionalCommands}
+
       exec "$@"
     '';
   };
diff --git a/local/pkgs/vasp/gnu/default.nix b/local/pkgs/vasp/gnu/default.nix
index d92b86a4..938c2230 100644
--- a/local/pkgs/vasp/gnu/default.nix
+++ b/local/pkgs/vasp/gnu/default.nix
@@ -1,6 +1,7 @@
 {
   stdenvNoCC, requireFile, writeShellApplication,
-  rsync, blas, scalapack, mpi, openmp, gfortran, gcc, fftwMpi, hdf5, wannier90
+  rsync, blas, scalapack, mpi, openmp, gfortran, gcc, fftwMpi, hdf5, wannier90,
+  additionalCommands ? ""
 }:
 let
   sources = import ../source.nix { inherit requireFile; };
@@ -47,6 +48,8 @@ let
       fi
       export OMP_NUM_THREADS
 
+      ${additionalCommands}
+
       exec "$@"
     '';
   };
diff --git a/local/pkgs/vasp/intel/default.nix b/local/pkgs/vasp/intel/default.nix
index 0239989e..d21c6139 100644
--- a/local/pkgs/vasp/intel/default.nix
+++ b/local/pkgs/vasp/intel/default.nix
@@ -1,6 +1,6 @@
 {
   buildFHSEnv, writeScript, stdenvNoCC, requireFile, substituteAll, symlinkJoin, writeTextDir,
-  config, oneapiArch ? config.oneapiArch or "SSE3",
+  config, oneapiArch ? config.oneapiArch or "SSE3", additionalCommands ? "",
   oneapi, gcc, glibc, lmod, rsync, which, wannier90, binutils, hdf5, zlib
 }:
 let
@@ -82,6 +82,8 @@ let
     # set OMP_STACKSIZE if not set
     export OMP_STACKSIZE=''${OMP_STACKSIZE-512M}
 
+    ${additionalCommands}
+
     ${
       if variant == "env" then ''exec "$@"''
       else
diff --git a/local/pkgs/vasp/nvidia/default.nix b/local/pkgs/vasp/nvidia/default.nix
index 66460449..51e281b9 100644
--- a/local/pkgs/vasp/nvidia/default.nix
+++ b/local/pkgs/vasp/nvidia/default.nix
@@ -1,6 +1,6 @@
 {
   buildFHSEnv, writeScript, stdenvNoCC, requireFile, substituteAll, symlinkJoin,
-  config, cudaCapabilities ? config.cudaCapabilities, nvhpcArch ? config.nvhpcArch or "px",
+  config, cudaCapabilities ? config.cudaCapabilities, nvhpcArch ? config.nvhpcArch or "px", additionalCommands ? "",
   nvhpc, lmod, mkl, gfortran, rsync, which, hdf5, wannier90, zlib
 }:
 let
@@ -67,6 +67,8 @@ let
     fi
     export OMP_NUM_THREADS
 
+    ${additionalCommands}
+
     ${
       if variant == "env" then ''exec "$@"''
       else