mirror of https://gitlab.com/scemama/QCaml.git
43 lines
884 B
OCaml
43 lines
884 B
OCaml
(** Electron-electron repulsion integrals *)
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open Constants
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open Util
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module Zm = struct
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let name = "Electron repulsion integrals"
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open Zero_m_parameters
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let zero_m z =
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let expo_pq_inv = z.expo_p_inv +. z.expo_q_inv in
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assert (expo_pq_inv <> 0.);
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let exp_pq = 1. /. expo_pq_inv in
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let t =
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if z.norm_pq_sq > integrals_cutoff then
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z.norm_pq_sq *. exp_pq
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else 0.
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in
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let maxm = z.maxm in
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let result = boys_function ~maxm t in
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let rec aux accu k = function
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| 0 -> result.(k) <- result.(k) *. accu
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| l ->
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begin
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result.(k) <- result.(k) *. accu;
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let new_accu = -. accu *. exp_pq in
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aux new_accu (k+1) (l-1)
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end
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in
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let f = two_over_sq_pi *. (sqrt exp_pq) in
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aux f 0 maxm;
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result
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end
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module M = TwoElectronIntegralsNonSeparable.Make(Zm)
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include M
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