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qp2/ocaml/Determinant.ml

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OCaml
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2019-01-25 11:39:31 +01:00
open Qptypes
open Sexplib.Std
type t = int64 array [@@deriving sexp]
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external to_int64_array : t -> int64 array = "%identity"
external of_int64_array_no_check : int64 array -> t = "%identity"
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let to_alpha_beta x =
let x = to_int64_array x in
let n_int = (Array.length x)/2 in
( Array.init n_int (fun i -> x.(i)) ,
Array.init n_int (fun i -> x.(i+n_int)) )
let to_bitlist_couple x =
let (xa,xb) = to_alpha_beta x in
let xa =
to_int64_array xa
|> Bitlist.of_int64_array
and xb =
to_int64_array xb
|> Bitlist.of_int64_array
in (xa,xb)
let bitlist_to_string ~mo_num x =
let len =
MO_number.to_int mo_num
in
let s =
List.map (function
| Bit.Zero -> "-"
| Bit.One -> "+"
) x
|> String.concat ""
in
String.sub s 0 len
let of_int64_array ~n_int ~alpha ~beta x =
assert ((Array.length x) = (N_int_number.to_int n_int)*2) ;
let (a,b) = to_bitlist_couple x
and alpha = Elec_alpha_number.to_int alpha
and beta = Elec_beta_number.to_int beta
in
if ( (Bitlist.popcnt a) <> alpha) then
begin
let mo_num = MO_number.get_max () in
let mo_num = MO_number.of_int mo_num ~max:mo_num in
failwith (Printf.sprintf "Expected %d electrons in alpha determinant
%s" alpha (bitlist_to_string ~mo_num:mo_num a) )
end;
if ( (Bitlist.popcnt b) <> beta ) then
begin
let mo_num = MO_number.get_max () in
let mo_num = MO_number.of_int mo_num ~max:mo_num in
failwith (Printf.sprintf "Expected %d electrons in beta determinant
%s" beta (bitlist_to_string ~mo_num:mo_num b) )
end;
x
let of_bitlist_couple ?n_int ~alpha ~beta (xa,xb) =
let ba, bb =
Bitlist.to_int64_array xa ,
Bitlist.to_int64_array xb
and n_int =
match n_int with
| Some x -> x
| None -> Bitlist.n_int_of_mo_num (List.length xa)
in
of_int64_array ~n_int ~alpha ~beta (Array.concat [ba;bb])
let to_string ~mo_num x =
let (xa,xb) = to_bitlist_couple x in
[ " " ; bitlist_to_string ~mo_num xa ; "\n" ;
" " ; bitlist_to_string ~mo_num xb ]
|> String.concat ""