Set number of "unique" atom types

[gasevic]

Since many different atom types can be introduced in the generation, the outcome can be just a collection of single atoms. Therefore, it would be helpful to restrict the generator to a fixed number of unique atom types so that more atoms have the same atom type.

This could easily be implemented to the .toml file. E.g:

max_num_atoms = 20
unique_atom_types = 4

This could lead to the molecule: C₅H₁₀I₂Cl₃

[marcelmbn]

Good idea! Should be simple. The only things to keep in mind during implementation:

• contradiction with the element_composition (too many different atoms expected)
• contradiction with max_num_atoms (if lower than unique_atom_types)
• contradiction with fixed_composition (unique_atom_types would be pointless anyway)