mirror of
https://gitlab.com/scemama/QCaml.git
synced 2024-11-13 17:43:41 +01:00
104 lines
3.0 KiB
OCaml
104 lines
3.0 KiB
OCaml
(* [[file:~/QCaml/perturbation/mp2.org::*Type][Type:2]] *)
|
|
type t = {
|
|
energy : float ;
|
|
mo_basis : Mo.Basis.t ;
|
|
frozen_core : Mo.Frozen_core.t ;
|
|
}
|
|
(* Type:2 ends here *)
|
|
|
|
|
|
|
|
(* | ~make~ | Creates an MP2 data structure |
|
|
*
|
|
* #+begin_example
|
|
* let mp2 =
|
|
* Perturbation.Mp2.make ~frozen_core:(Mo.Frozen_core.(make Small nuclei)) mo_basis
|
|
* ;;
|
|
* val mp2 : Perturbation.Mp2.t = E(MP2)=-0.185523
|
|
* #+end_example *)
|
|
|
|
|
|
(* [[file:~/QCaml/perturbation/mp2.org::*Creation][Creation:2]] *)
|
|
open Linear_algebra
|
|
|
|
let make_rmp2 mo_basis mo_class =
|
|
|
|
let epsilon = Mo.Basis.mo_energies mo_basis in
|
|
let eri = Mo.Basis.ee_ints mo_basis in
|
|
|
|
let inactives =
|
|
List.filter (fun i ->
|
|
match i with Mo.Class.Inactive _ -> true | _ -> false) mo_class
|
|
and virtuals =
|
|
List.filter (fun i ->
|
|
match i with Mo.Class.Virtual _ -> true | _ -> false) mo_class
|
|
in
|
|
|
|
List.fold_left (fun accu b ->
|
|
match b with Mo.Class.Virtual b ->
|
|
let eps = -. (epsilon%.(b)) in
|
|
accu +.
|
|
List.fold_left (fun accu a ->
|
|
match a with Mo.Class.Virtual a ->
|
|
let eps = eps -. (epsilon%.(a)) in
|
|
accu +.
|
|
List.fold_left (fun accu j ->
|
|
match j with Mo.Class.Inactive j ->
|
|
let eps = eps +. epsilon%.(j) in
|
|
accu +.
|
|
List.fold_left (fun accu i ->
|
|
match i with Mo.Class.Inactive i ->
|
|
let eps = eps +. epsilon%.(i) in
|
|
let ijab = Four_idx_storage.get_phys eri i j a b
|
|
and abji = Four_idx_storage.get_phys eri a b j i in
|
|
let abij = ijab in
|
|
accu +. ijab *. ( abij +. abij -. abji) /. eps
|
|
| _ -> accu
|
|
) 0. inactives
|
|
| _ -> accu
|
|
) 0. inactives
|
|
| _ -> accu
|
|
) 0. virtuals
|
|
| _ -> accu
|
|
) 0. virtuals
|
|
|
|
|
|
let make ~frozen_core mo_basis =
|
|
|
|
let mo_class =
|
|
Mo.Class.cas_sd mo_basis ~frozen_core 0 0
|
|
|> Mo.Class.to_list
|
|
in
|
|
|
|
let energy =
|
|
match Mo.Basis.mo_type mo_basis with
|
|
| RHF -> make_rmp2 mo_basis mo_class
|
|
| ROHF -> Common.Util.not_implemented "ROHF MP2"
|
|
| UHF -> Common.Util.not_implemented "UHF MP2"
|
|
| _ -> invalid_arg "MP2 needs RHF or ROHF MOs"
|
|
in
|
|
{ energy ; mo_basis ; frozen_core }
|
|
(* Creation:2 ends here *)
|
|
|
|
|
|
|
|
(* | ~energy~ | Returns the MP2 energy |
|
|
* | ~mo_basis~ | Returns the MO basis on which the MP2 energy was computed |
|
|
* | ~frozen_core~ | Returns the frozen_core scheme used to compute the MP2 energy |
|
|
*
|
|
* #+begin_example
|
|
*
|
|
* #+end_example *)
|
|
|
|
|
|
(* [[file:~/QCaml/perturbation/mp2.org::*Access][Access:2]] *)
|
|
let energy t = t.energy
|
|
let mo_basis t = t.mo_basis
|
|
let frozen_core t = t.frozen_core
|
|
(* Access:2 ends here *)
|
|
|
|
(* [[file:~/QCaml/perturbation/mp2.org::*Printers][Printers:2]] *)
|
|
let pp ppf t =
|
|
Format.fprintf ppf "@[E(MP2)=%f@]" t.energy
|
|
(* Printers:2 ends here *)
|