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QCaml/Basis/Shell_pair.ml

129 lines
3.9 KiB
OCaml

open Util
open Constants
type t = {
expo : float; (* alpha + beta *)
expo_inv : float; (* 1/(alpha + beta) *)
center : Coordinate.t; (* P = (alpha * A + beta B)/(alpha+beta) *)
center_a : Coordinate.t; (* P - A *)
center_ab: Coordinate.t; (* A - B *)
norm_sq : float; (* |A-B|^2 *)
norm_coef: float; (* norm_coef_a * norm_coef_b *)
coef : float; (* norm_coef * coef_a * coef_b * g, with
g = (pi/(alpha+beta))^(3/2) exp (-|A-B|^2 * alpha*beta/(alpha+beta)) *)
norm_coef_scale : float array; (* norm_coef.(i) / norm_coef.(0) *)
i : int;
j : int;
shell_a : Contracted_shell.t;
shell_b : Contracted_shell.t;
monocentric : bool
}
exception Null_contribution
let create_array ?cutoff p_a p_b =
let cutoff, log_cutoff =
match cutoff with
| None -> -1., max_float
| Some cutoff -> cutoff, -. (log cutoff)
in
let center_ab = Coordinate.(
Contracted_shell.center p_a |- Contracted_shell.center p_b )
in
let norm_sq =
Coordinate.dot center_ab center_ab
in
let norm_coef_scale_a =
Contracted_shell.norm_coef_scale p_a
and norm_coef_scale_b =
Contracted_shell.norm_coef_scale p_b
in
let norm_coef_scale =
Array.map (fun v1 ->
Array.map (fun v2 -> v1 *. v2) norm_coef_scale_b
) norm_coef_scale_a
|> Array.to_list
|> Array.concat
in
Array.init (Contracted_shell.size p_a) (fun i ->
let p_a_expo_center = Coordinate.(
Contracted_shell.expo p_a i |. Contracted_shell.center p_a )
in
let norm_coef_a =
Contracted_shell.norm_coef p_a i
in
Array.init (Contracted_shell.size p_b) (fun j ->
try
let norm_coef_b =
Contracted_shell.norm_coef p_b j
in
let norm_coef =
norm_coef_a *. norm_coef_b
in
if (norm_coef < cutoff) then
raise Null_contribution;
let p_b_expo_center = Coordinate.(
Contracted_shell.expo p_b j |. Contracted_shell.center p_b )
in
let expo = Contracted_shell.(expo p_a i +. expo p_b j) in
let expo_inv = 1. /. expo in
let center = Coordinate.(
expo_inv |. (p_a_expo_center |+ p_b_expo_center ) )
in
let argexpo =
Contracted_shell.(expo p_a i *. expo p_b j) *. norm_sq *. expo_inv
in
if (argexpo > log_cutoff) then
raise Null_contribution;
let g =
(pi *. expo_inv)**(1.5) *. exp(-. argexpo)
in
let coef =
norm_coef *. Contracted_shell.(coef p_a i *. coef p_b j) *. g
in
if (abs_float coef < cutoff) then
raise Null_contribution;
let center_a =
Coordinate.(center |- Contracted_shell.center p_a)
in
let monocentric =
Contracted_shell.center p_a = Contracted_shell.center p_b
in
Some { i ; j ; shell_a=p_a ; shell_b=p_b ; norm_coef ; coef ; expo ; expo_inv ; center ; center_a ; center_ab ; norm_sq ; norm_coef_scale ; monocentric }
with
| Null_contribution -> None
)
)
|> Array.to_list
|> Array.concat
|> Array.to_list
|> List.filter (function Some _ -> true | None -> false)
|> List.map (function Some x -> x | None -> assert false)
|> Array.of_list
let hash a =
Hashtbl.hash (a.expo, a.center_a, a.center_ab, a.coef)
let cmp a b =
hash a - hash b
let shell_pairs basis =
Array.mapi (fun i shell_a -> Array.map (fun shell_b ->
create_array shell_a shell_b) (Array.sub basis 0 (i+1)) ) basis
let unique_shell_pairs basis =
let map =
Hashtbl.create 129
in
Array.iter (fun spa ->
Array.iter (fun value ->
let key = hash value in
Hashtbl.add map key value) spa) basis;
map