From f4f31db614f2e755a66a93ea7f095382fc2c986f Mon Sep 17 00:00:00 2001
From: Anthony Scemama <scemama@irsamc.ups-tlse.fr>
Date: Tue, 27 Mar 2018 19:32:37 +0200
Subject: [PATCH] Changed integral storage to Float32

---
 Basis/ERI.ml             |  2 +-
 Utils/FourIdxStorage.ml  |  5 +++--
 Utils/FourIdxStorage.mli | 25 +++++++++++++++++++++++++
 3 files changed, 29 insertions(+), 3 deletions(-)
 create mode 100644 Utils/FourIdxStorage.mli

diff --git a/Basis/ERI.ml b/Basis/ERI.ml
index 675ab55..577b85c 100644
--- a/Basis/ERI.ml
+++ b/Basis/ERI.ml
@@ -77,7 +77,7 @@ let filter_contracted_shell_pairs ?(cutoff=integrals_cutoff) shell_pairs =
         | Some cspc -> 
           let cls = class_of_contracted_shell_pair_couple cspc in
           (pair, Zmap.fold (fun key value accu -> max (abs_float value) accu) cls 0. )
-        | None -> (pair, -1.)
+        | None -> (pair, -1.) 
     ) shell_pairs
   |> List.filter (fun (_, schwartz_p_max) -> schwartz_p_max >= cutoff)
   |> List.map fst
diff --git a/Utils/FourIdxStorage.ml b/Utils/FourIdxStorage.ml
index 4390701..a90e1f9 100644
--- a/Utils/FourIdxStorage.ml
+++ b/Utils/FourIdxStorage.ml
@@ -2,8 +2,9 @@ let max_index = 1 lsl 14
 
 type index_pair = { first : int ; second : int }
 
+
 type storage_t = 
-  | Dense  of (float, Bigarray.float64_elt, Bigarray.fortran_layout) Bigarray.Genarray.t
+  | Dense  of (float, Bigarray.float32_elt, Bigarray.fortran_layout) Bigarray.Genarray.t
   | Sparse of (int, float) Hashtbl.t
 
 type t =
@@ -81,7 +82,7 @@ let create ~size sparsity =
     match sparsity with
     | `Dense ->
       let result = 
-        Bigarray.Genarray.create Float64 Bigarray.fortran_layout [| size ; size ; size ; size |]
+        Bigarray.Genarray.create Float32 Bigarray.fortran_layout [| size ; size ; size ; size |]
       in
       Bigarray.Genarray.fill result 0.;
       Dense result
diff --git a/Utils/FourIdxStorage.mli b/Utils/FourIdxStorage.mli
new file mode 100644
index 0000000..78f9656
--- /dev/null
+++ b/Utils/FourIdxStorage.mli
@@ -0,0 +1,25 @@
+(** Storage for four-index data (integrals, density matrices, ...).
+
+There are two kinds of ordering of indices:
+
+- Physicist's : { \[ \langle i j | k l \rangle \] }
+- Chemist's   : { \[ ( i j | k l ) \] }
+
+*)
+
+type t
+
+val create : size:int -> [< `Dense | `Sparse ] -> t
+(** If [`Dense] is chosen, internally the data is stored as a 4-dimensional
+    [Bigarray]. Else, it is stored as a hash table.
+*)
+
+(** {2 Accessors} *)
+val get_chem : t -> int -> int -> int -> int -> float
+val get_phys : t -> int -> int -> int -> int -> float
+val set_chem : t -> int -> int -> int -> int -> float -> unit
+val set_phys : t -> int -> int -> int -> int -> float -> unit
+
+(** {2 I/O} *)
+val to_file : ?cutoff:float -> filename:string -> t -> unit
+(** Write the data to file, using the physicist's ordering. *)