Hi @prehner ,

I'm working on micelle self-assembly using the gc-PCSAFT functional in FeOs, and I have a question about curved-interface support in the Python DFT API.

I see that the Geometry enum includes a Spherical option, and that it is used for confined systems (e.g., spherical pores via Pore1D). What I am unsure about is whether this same spherical geometry can be used to model a free spherical interface (micelle or droplet) where the external potential is zero (V_ext = 0).

Essentially, I'm looking for the spherical analogue of planar_interface:
a way to solve the Euler–Lagrange equation for a free curved interface rather than a confined one.

My questions:
1. Is modeling a free spherical interface already supported in the current API?
2. If not, is there an intended pathway in the architecture for implementing this?
3. Are there specific challenges or design considerations to keep in mind for extending the DFT solver to free spherical geometry?

I would be very happy to contribute to the implementation if this functionality aligns with the project’s plans or would be useful to others.

Thank you for your time and for maintaining this excellent tool.

Best regards,
Emad