anchor.diff:  
       gamess-mkl = callPackage ./gamess { mathlib=callPackage ./mkl { } ; useMkl = true; };
   
  -    octopus = pkgs.octopus;
  -
       ga = callPackage ./ga { ssh=openssh; };
   
  +    libxc = pkgs.libxc;
  +
       nwchem = callPackage ./nwchem { };
  +
  +    octopus = pkgs.octopus;
   
       openmolcas = callPackage ./openmolcas {
         texLive = texlive.combine { inherit (texlive) scheme-basic epsf cm-super; };
  
positive.code: 
      qdng = callPackage ./qdng { };
  
      libfabric = callPackage ./libfabric { };
  
      libint = callPackage ./libint { };
  
      libxc = pkgs.libxc;
  
      mkl = callPackage ./mkl { };
  
      ibsim = callPackage ./ibsim { };
  
      impi = callPackage ./impi { };
  
      infiniband-diags = callPackage ./infiniband-diags { };
  
      openshmem = callPackage ./openshmem {};
  
  
negative.code: 
    pkgs-qc = with pkgs; {
  
      ### Quantum Chem
      cp2k = callPackage ./cp2k { };
  
      molden = pkgs.molden;
  