diff --git a/debian/var/models/schemas/model_0.1.xmls b/debian/var/models/schemas/model_0.1.xmls
index 3d17c89..f4296dd 100644
--- a/debian/var/models/schemas/model_0.1.xmls
+++ b/debian/var/models/schemas/model_0.1.xmls
@@ -13,6 +13,9 @@
 <xs:attribute name="sequence" type="xs:integer"/>
 <xs:attribute name="probability" type="xs:integer"/>
 <xs:attribute name="parent" type="xs:string"/>
+<xs:attribute name="x" type="xs:integer" default="0"/>
+<xs:attribute name="y" type="xs:integer" default="0"/>
+<xs:attribute name="z" type="xs:integer" default="0"/>
 
 
 <xs:attributeGroup name="id_date_author">
@@ -21,6 +24,12 @@
       <xs:attribute ref="author"/>
 </xs:attributeGroup>
 
+<xs:attributeGroup name="x_y_z">
+      <xs:attribute ref="x"/>
+      <xs:attribute ref="y"/>
+      <xs:attribute ref="z"/>
+</xs:attributeGroup>
+
 <xs:element name="ref">
     <xs:complexType>
         <xs:simpleContent>
@@ -39,9 +48,7 @@
         <xs:sequence>
             <xs:element minOccurs="0" ref="quote"/>
         </xs:sequence>
-        <xs:attribute name="x" type="xs:integer" default="1"/>
-        <xs:attribute name="y" type="xs:integer" default="0"/>
-        <xs:attribute name="z" type="xs:integer" default="0"/>
+        <xs:attributeGroup ref="x_y_z"/>
         <xs:attribute name="site" type="xs:integer" default="1"/>
         <xs:attribute name="weight" type="xs:integer" default="0"/>
     </xs:complexType>
@@ -123,9 +130,9 @@
                 <xs:complexType>
                 <xs:sequence>
 
-                    <xs:element name="max_thread"/>
+                    <xs:element name="max_thread" type="xs:integer"/>
 
-                    <xs:element name="max_cycles"/>
+                    <xs:element name="max_cycles" type="xs:integer"/>
 
                 </xs:sequence>
                 </xs:complexType>
@@ -135,11 +142,15 @@
                 <xs:complexType>
                 <xs:sequence>
 
-                    <xs:element name="dimension"/>
+                    <xs:element name="dimension" type="xs:integer"/>
 
-                    <xs:element name="size"/>
+                    <xs:element name="size">
+                        <xs:complexType>
+                            <xs:attributeGroup ref="x_y_z"/>
+                        </xs:complexType>
+                    </xs:element>
 
-                    <xs:element name="site_multiplicity"/>
+                    <xs:element name="site_multiplicity" type="xs:integer"/>
 
               </xs:sequence>
               </xs:complexType>