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mirror of https://github.com/QuantumPackage/qp2.git synced 2024-12-30 15:15:38 +01:00
qp2/ocaml/Determinant.ml

64 lines
1.5 KiB
OCaml

open Qptypes
open Sexplib.Std
type t = int64 array [@@deriving sexp]
external to_int64_array : t -> int64 array = "%identity"
external of_int64_array_no_check : int64 array -> t = "%identity"
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 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
failwith (Printf.sprintf "Expected %d electrons in alpha determinant
%s" alpha (Bitlist.to_string a) )
end;
if ( (Bitlist.popcnt b) <> beta ) then
begin
failwith (Printf.sprintf "Expected %d electrons in beta determinant
%s" beta (Bitlist.to_string 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
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 xa ; "\n" ;
" " ; Bitlist.to_string xb ]
|> String.concat ""