anchor.diff:  
       buildInputs = [
         gau2grid
  -      libxc
  +      libxc_
         blas
         lapack
         dkh_
  
positive.code: { lib, stdenv, buildPythonPackage, buildPackages, makeWrapper, fetchFromGitHub, fetchurl, pkg-config
  , writeTextFile, cmake, ninja, perl, gfortran, python, pybind11, qcelemental, qcengine, numpy, pylibefp
  , deepdiff, blas, lapack, gau2grid, libxc, dkh, dftd3, pcmsolver, libefp, libecpint, cppe
  , chemps2, hdf5, hdf5-cpp, pytest, mpfr, gmpxx, eigen, boost, adcc
  
negative.code:       "-DLibint2_DIR=${libint}/share/cmake/Libint2"
        # libxc
        "-DCMAKE_INSIST_FIND_PACKAGE_Libxc=ON"
        "-DLibxc_DIR=${libxc_}/share/cmake/Libxc"
        # pcmsolver
        "-DCMAKE_INSIST_FIND_PACKAGE_PCMSolver=ON"
        "-DENABLE_PCMSolver=ON"
  