open Powers exception AngularMomentumError of string type t = | S | P | D | F | G | H | I | J | K | L | M | N | O let of_char = function | 's' | 'S' -> S | 'p' | 'P' -> P | 'd' | 'D' -> D | 'f' | 'F' -> F | 'g' | 'G' -> G | 'h' | 'H' -> H | 'i' | 'I' -> I | 'j' | 'J' -> J | 'k' | 'K' -> K | 'l' | 'L' -> L | 'm' | 'M' -> M | 'n' | 'N' -> N | 'o' | 'O' -> O | c -> raise (AngularMomentumError (String.make 1 c)) let to_string = function | S -> "S" | P -> "P" | D -> "D" | F -> "F" | G -> "G" | H -> "H" | I -> "I" | J -> "J" | K -> "K" | L -> "L" | M -> "M" | N -> "N" | O -> "O" let to_char = function | S -> 'S' | P -> 'P' | D -> 'D' | F -> 'F' | G -> 'G' | H -> 'H' | I -> 'I' | J -> 'J' | K -> 'K' | L -> 'L' | M -> 'M' | N -> 'N' | O -> 'O' let to_int = function | S -> 0 | P -> 1 | D -> 2 | F -> 3 | G -> 4 | H -> 5 | I -> 6 | J -> 7 | K -> 8 | L -> 9 | M -> 10 | N -> 11 | O -> 12 let of_int = function | 0 -> S | 1 -> P | 2 -> D | 3 -> F | 4 -> G | 5 -> H | 6 -> I | 7 -> J | 8 -> K | 9 -> L | 10 -> M | 11 -> N | 12 -> O | c -> raise (AngularMomentumError (string_of_int c)) type kind = | Singlet of t | Doublet of (t*t) | Triplet of (t*t*t) | Quartet of (t*t*t*t) let n_functions a = let a = to_int a in (a*a + 3*a + 2)/2 (** Returns an array of Zkeys corresponding to all possible angular momenta *) let zkey_array a = let keys_1d l = let create_z { x ; y ; _ } = Powers.of_int_tuple (x,y,l-(x+y)) in let rec create_y accu xyz = let { x ; y ; z } = xyz in match y with | 0 -> (create_z xyz)::accu | i -> let ynew = y-1 in create_y ( (create_z xyz)::accu) (Powers.of_int_tuple (x,ynew,z)) in let rec create_x accu xyz = let { x ; y ; z } = xyz in match x with | 0 -> (create_y [] xyz)@accu | i -> let xnew = x-1 in let ynew = l-xnew in create_x ((create_y [] xyz)@accu) (Powers.of_int_tuple (xnew, ynew, z)) in create_x [] (Powers.of_int_tuple (l,0,0)) |> List.rev in begin match a with | Singlet l1 -> List.map (fun x -> Zkey.of_powers (Zkey.Three x)) (keys_1d @@ to_int l1) | Doublet (l1, l2) -> List.map (fun a -> List.map (fun b -> Zkey.of_powers (Zkey.Six (a,b))) (keys_1d @@ to_int l2) ) (keys_1d @@ to_int l1) |> List.concat | Triplet (l1, l2, l3) -> List.map (fun a -> List.map (fun b -> List.map (fun c -> Zkey.of_powers (Zkey.Nine (a,b,c))) (keys_1d @@ to_int l3) ) (keys_1d @@ to_int l2) |> List.concat ) (keys_1d @@ to_int l1) |> List.concat | Quartet (l1, l2, l3, l4) -> List.map (fun a -> List.map (fun b -> List.map (fun c -> List.map (fun d -> Zkey.of_powers (Zkey.Twelve (a,b,c,d))) (keys_1d @@ to_int l4) ) (keys_1d @@ to_int l3) |> List.concat ) (keys_1d @@ to_int l2) |> List.concat ) (keys_1d @@ to_int l1) |> List.concat end |> Array.of_list