anchor.diff:      AR         = ar -r
       DFLAGS     = -D__FFTW3 -D__LIBXC -D__LIBINT -D__parallel -D__SCALAPACK \
                    -D__MPI_VERSION=3 -D__F2008 -D__LIBXSMM -D__SPGLIB \
  -                 -D__MAX_CONTR=4 -D__LIBVORI
  +                 -D__MAX_CONTR=4 -D__LIBVORI -D__ELPA
       CFLAGS    = -fopenmp
       FCFLAGS    = \$(DFLAGS) -O2 -ffree-form -ffree-line-length-none \
                    -ftree-vectorize -funroll-loops -msse2 \
                    -std=f2008 \
                    -fopenmp -ftree-vectorize -funroll-loops \
                    -I${libxc}/include -I${libxsmm}/include \
  -                 -I${libint}/include
  +                 -I${libint}/include $(pkg-config --variable=fcflags elpa)
       LIBS       = -lfftw3 -lfftw3_threads \
                    -lscalapack -lblas -llapack \
                    -lxcf03 -lxc -lxsmmf -lxsmm -lsymspg \
                    -lint2 -lstdc++ -lvori \
                    -lgomp -lpthread -lm \
  -                 -fopenmp
  +                 -fopenmp $(pkg-config --libs elpa)
       LDFLAGS    = \$(FCFLAGS) \$(LIBS)
       EOF
     '';
  
positive.code:     fetchSubmodules = true;
    };
  
    nativeBuildInputs = [ python3 which openssh makeWrapper ];
    buildInputs = [
      gfortran
      fftw
      gsl
  
negative.code: { lib, stdenv, fetchFromGitHub, python3, gfortran, blas, lapack
  , fftw, libint, libvori, libxc, mpi, gsl, scalapack, openssh, makeWrapper
  , libxsmm, spglib, which, elpa, pkg-config
  } :
  
  let
  