anchor.diff:                   -D__MPI_VERSION=3 -D__F2008 -D__LIBXSMM -D__SPGLIB \
                    -D__MAX_CONTR=4
   
  +    CFLAGS    = -fopenmp
       FCFLAGS    = \$(DFLAGS) -O2 -ffree-form -ffree-line-length-none \
                    -ftree-vectorize -funroll-loops -msse2 \
                    ${stdenv.lib.optionalString optAVX "-mavx -mavx2"} \
  
positive.code:     owner = "cp2k";
      repo = "cp2k";
      rev = "v${version}";
      sha256 = "0icmzqc9v8rvcw8xg295qpa7h3d1vpjbc89l0lvakam977ianblf";
      fetchSubmodules = true;
    };
  
    nativeBuildInputs = [ python which openssh makeWrapper ];
    buildInputs = [ gfortran fftw gsl libint2 libxc libxsmm  spglib blas lapack mpi scalapack ];
  
    makeFlags = [
  
negative.code: { stdenv, fetchFromGitHub, python3, gfortran, blas, lapack
  , fftw, libint2, libxc, mpi, gsl, scalapack, openssh, makeWrapper
  , libxsmm, spglib, which
  , optAVX ? false
  