anchor.diff:  { lib, buildPythonPackage, buildPackages, makeWrapper, fetchFromGitHub, fetchurl, pkg-config
   , writeTextFile, cmake, perl, gfortran, python, pybind11, qcelemental, qcengine, numpy, pylibefp
  -, deepdiff, mkl, gau2grid, libxc, dkh, dftd3, pcmsolver, libefp, chemps2, hdf5, hdf5-cpp
  +, deepdiff, blas, lapack, gau2grid, libxc, dkh, dftd3, pcmsolver, libefp, chemps2, hdf5, hdf5-cpp
   , pytest, mpfr, gmpxx, eigen, boost
   } :
   
  
positive.code:         --subst-var out
      '';
  
      doCheck = false;
      checkPhase = ''
        runHook preCheck
        ctest -j $NIX_BUILD_CORES
      '';
  
      doInstallCheck = true;
      installCheckPhase = ''
        export OMP_NUM_THREADS=2
  
negative.code:       rev = "v${version}";
        sha256 = "sha256-NVpE5fAVWYlkymTrvptZ7xqu68eVy71YJ+dRdBMMU9c=";
      };
  
      # Required for Libint compilation. g++ will otherwise not be able to link the large amount of files.
      preConfigure = ''
  