Function compute_ani 

pub fn compute_ani(
    elements: &[u8],
    positions: &[[f64; 3]],
) -> Result<AniResult, String>

Compute ANI neural-network potential energy (and optionally forces).

Uses internally-generated test weights — suitable for testing and demonstration. For physically meaningful results, use ani::compute_ani() with trained weights.

elements: atomic numbers (supported: H, C, N, O, F, S, Cl). positions: Cartesian coordinates in Å, one [x,y,z] per atom.