{ requireFile }: requireFile
{
  name = "vasp.6.4.3.tgz";
  # nix-prefetch-url file://$(pwd)/vasp.6.4.3.tgz
  sha256 = "1x14dixils77rr4c6yqmxkvyzgfz6906badsw2shksd3y9ryfc7y";
  message = "Source file not found.";
}