type point = Point.t

type bohr = Bohr.t
type angstrom = Angstrom.t

let a_to_b a = Constants.a0_inv *. a
let b_to_a b = Constants.a0     *. b

let bohr_to_angstrom { Bohr.x ; y ; z } = 
  Angstrom.make 
  {
    Point.
    x = b_to_a x ;
    y = b_to_a y ;
    z = b_to_a z ;
  }

let angstrom_to_bohr { Angstrom.x ; y ; z } =  
  Bohr.make 
  {
    Point.
    x = a_to_b x ;
    y = a_to_b y ;
    z = a_to_b z ;
  }