diff --git a/Nuclei/Charge.mli b/Nuclei/Charge.mli
index a54e81a..bc455bf 100644
--- a/Nuclei/Charge.mli
+++ b/Nuclei/Charge.mli
@@ -1,13 +1,12 @@
+(** This type should be used for all charges in the program (electrons, nuclei,...). *)
+
 type t = private float
 
-(** Float conversion functions *)
 val to_float : t -> float
 val of_float : float -> t
 
-(** Int conversion functions *)
 val to_int   : t -> int
 val of_int   : int -> t
 
-(** String conversion functions *)
 val to_string: t -> string 
 val of_string: string -> t
diff --git a/Nuclei/Element.mli b/Nuclei/Element.mli
index 2f8cba7..9cf2c97 100644
--- a/Nuclei/Element.mli
+++ b/Nuclei/Element.mli
@@ -1,3 +1,5 @@
+(** Chemical elements. *)
+
 exception ElementError of string
 
 type t =
@@ -10,10 +12,35 @@ type t =
                            |Pt          
 
 
-(** String conversion functions *)
 val of_string : string -> t
+(** Creates an {!Element.t} from a chemical symbol or from the full name of the
+  element (case insensitive).
+  @raise ElementError upon failure
+
+Examples:
+
+{[
+Element.of_string "Fe" -> Element.Fe
+Element.of_string "hydrogen" -> Element.H
+Element.of_string "pouet" -> ElementError "Element pouet unknown"
+]}
+  *)
+
 val to_string : t -> string
+(** Gets the chemical symbol of the {!Element.t} in a string.
+
+Example:
+
+[Element.(to_string Fe) -> "Fe"]
+*)
+
 val to_long_string : t -> string
+(** Gets the full name of the {!Element.t} in a string.
+
+Example:
+
+[Element.(to_long_string Fe) -> "Iron"]
+*)
 
 (** Properties *)
 val to_int : t -> int 
diff --git a/Utils/Angstrom.mli b/Utils/Angstrom.mli
index fa6fd98..b68535e 100644
--- a/Utils/Angstrom.mli
+++ b/Utils/Angstrom.mli
@@ -8,4 +8,5 @@ type t = private {
 
 
 val make : Point.t -> t
+(** Create from a {!Point.t}. *)
 
diff --git a/Utils/Bohr.mli b/Utils/Bohr.mli
index dd46b40..e5f8e96 100644
--- a/Utils/Bohr.mli
+++ b/Utils/Bohr.mli
@@ -8,5 +8,6 @@ type t = private {
 
 
 val make : Point.t -> t
+(** Create from a {!Point.t}. *)
 
 
diff --git a/Utils/Electrons.mli b/Utils/Electrons.mli
index c5f750c..c85b048 100644
--- a/Utils/Electrons.mli
+++ b/Utils/Electrons.mli
@@ -1,9 +1,9 @@
 (** Information related to electrons. *)
 
 type t = {
-  n_alpha : int ;  (** Number of alpha electrons *)
-  n_beta  : int ;  (** Number of beta  electrons *)
-  multiplicity : int; (** Spin multiplicity: 2S+1 *)
+  n_alpha      : int ;  (** Number of alpha electrons *)
+  n_beta       : int ;  (** Number of beta  electrons *)
+  multiplicity : int ;  (** Spin multiplicity: 2S+1 *)
 }