main.rs

struct Atom {
    position: [f32; 3],
    epsilon: f32,
    sigma: f32,
}

impl Atom {
    fn new(x: f32, y: f32, z: f32, epsilon: f32, sigma: f32) -> Atom {
        Atom {
            position: [x, y, z],
            sigma: sigma,
            epsilon: epsilon,
        }
    }
}

struct Box {
    a: f32,
    b: f32,
    c: f32,
    atoms: &mut Vec<Atom>,
}

impl Box {
    fn new(a: f32, b: f32, c: f32, atoms: &mut Vec<Atom>) -> Box {
        Box {
            a: a,
            b: b,
            c: c,
            atoms: atoms,
        }
    }
}

fn main() {
    let mut a1 = Atom::new(0., 0., 0., 1., 1.);
    let mut a2 = Atom::new(5., 5., 5., 1., 1.);
    let mut atoms = vec![a1, a2];
    let b = Box(10., 10., 10., &mut atoms);
    println!("{}", b.atoms[0].position[0]);
}