(** Data structure to represent the molecular orbitals.  *)
open Lacaml.D

type mo_class =
| Core of int
| Inactive of int
| Active of int
| Virtual of int
| Deleted of int


type mo_type =
| RHF | ROHF | CASSCF
| Natural of string
| Localized of string


type t = private
{
  ao_basis        : AOBasis.t;         (* Atomic basis set on which the MOs are built. *)
  mo_type         : mo_type;           (* Kind of MOs (RHF, CASSCF, Localized...       *)
  mo_class        : mo_class array;    (* CI-Class of the MOs *)
  mo_occupation   : Vec.t;             (* Occupation numbers *)
  mo_coef         : Mat.t;             (* Matrix of the MO coefficients in the AO basis *)
  eN_ints         : NucInt.t lazy_t;   (* Electron-nucleus potential integrals *)
  ee_ints         : ERI.t lazy_t;      (* Electron-electron potential integrals *)
  kin_ints        : KinInt.t lazy_t;   (* Kinetic energy integrals *)
}



val make :  ao_basis:AOBasis.t ->
            mo_type:mo_type ->
            mo_class:mo_class array ->
            mo_occupation:Vec.t ->
            mo_coef:Mat.t ->
            unit -> t
(** Function to build a data structure representing the molecular orbitals. *)

val of_hartree_fock : frozen_core:bool -> HartreeFock_type.t -> t
(** Build MOs from a Restricted Hartree-Fock calculation. *)