17  typedef std::vector<Atom>::iterator iterator;
 
   23  Atom operator[](std::size_t idx);
 
   25  iterator begin() 
noexcept { 
return (_atoms.begin()); }
 
   27  iterator end() 
noexcept { 
return (_atoms.end()); }
 
   31  const double &getMass() 
const;
 
   33  std::vector<std::array<double, 3>> 
const &getDimensions() 
const;
 
   35  std::vector<std::vector<int>> &getBonds();
 
   38  std::vector<Atom> _atoms;
 
   42  std::vector<std::array<double, 3>> _dimensions;
 
   44  std::vector<std::vector<int>> _bonds;