Came to my mind this design and made it as simple as possible on tinkercard
Basic structure of a deoxyribonucleotide (specifically, a adenine)
Yes, ...some bonds are inaccurate but tried to keep it simple and solid as possible.
The adenine base cup has an opening which is intentional as it is intended for a calculator or a notebook:
-Organizer_1 has a narrower opening (printed model is this one)
seems solid enough with 10% infill but would suggest 3 or 4 shells since a fall may break a part (never tested though, its intended as a top desk item)