anchor.diff:      owner = "cp2k";
       repo = "cp2k";
       rev = "v${version}";
  -    sha256 = "0icmzqc9v8rvcw8xg295qpa7h3d1vpjbc89l0lvakam977ianblf";
  +    sha256 = "1qv7gprmm9riz9jj82n0mh2maij137h3ivh94z22bnm75az86jcs";
       fetchSubmodules = true;
     };
   
  -  nativeBuildInputs = [ python which openssh makeWrapper ];
  +  nativeBuildInputs = [ python3 which openssh makeWrapper ];
     buildInputs = [ gfortran fftw gsl libint2 libxc libxsmm  spglib blas lapack mpi scalapack ];
   
     makeFlags = [
  
positive.code:                  -D__MPI_VERSION=3 -D__F2008 -D__LIBXSMM -D__SPGLIB \
                   -D__MAX_CONTR=4
  
      FCFLAGS    = \$(DFLAGS) -O2 -ffree-form -ffree-line-length-none \
                   -ftree-vectorize -funroll-loops -msse2 \
                   ${stdenv.lib.optionalString optAVX "-mavx -mavx2"} \
  
negative.code:   enableParallelBuilding = true;
  
    postPatch = ''
      patchShebangs tools exts/dbcsr/tools/build_utils exts/dbcsr/.cp2k
      substituteInPlace exts/dbcsr/.cp2k/Makefile --replace '/usr/bin/env python3' '${python3}/bin/python'
    '';
  
    configurePhase = ''
      cat > arch/${arch}.${cp2kVersion} << EOF
      CC         = mpicc
      CPP        =
      FC         = mpif90
      LD         = mpif90
  