diff --git a/bin/c1.js b/bin/c1.js
index d9211c2..ed9c21f 100644
--- a/bin/c1.js
+++ b/bin/c1.js
@@ -1,15 +1,16 @@
 {
-"projectile":[11.99, 6.0],
+"projectile":[11.99671, 6],
 "energy": 1000,
-"material":[{"A":12,
+"material":[{"A":12.0107,
             "Z":6,
             "thickness":1.0
             },
             {
-            "A":56,
+            "A":55.845,
             "Z":26,
             "density":7.8,
             "thickness":0.05
             }
-            ]
+            ],
+"config":"atimav1.4"
 }
diff --git a/bin/c2.js b/bin/c2.js
index 5d0e199..2d2a99c 100644
--- a/bin/c2.js
+++ b/bin/c2.js
@@ -1,16 +1,16 @@
 {
-"projectile":[11.99, 6.0],
+"projectile":[11.99671, 6],
 "energy":{
     "min": 100,
     "max": 1000,
     "step": 100
     },
-"material":[{"A":12,
+"material":[{"A":12.0107,
             "Z":6,
             "thickness":1.0
             },
             {
-            "A":56,
+            "A":55.845,
             "Z":26,
             "density":7.8,
             "thickness":0.05
diff --git a/bin/c3.js b/bin/c3.js
index ab5957d..0e4cde8 100644
--- a/bin/c3.js
+++ b/bin/c3.js
@@ -1,5 +1,5 @@
 {
-"projectile":[11.99, 6.0],
+"projectile":[11.99671, 6],
 "energy":{
     "min": 100,
     "max": 1000,
diff --git a/bin/catima_calculator.cpp b/bin/catima_calculator.cpp
index 0990453..fd66913 100644
--- a/bin/catima_calculator.cpp
+++ b/bin/catima_calculator.cpp
@@ -27,6 +27,7 @@ int main( int argc, char * argv[] )
     Projectile projectile;
     Layers layers;
     std::vector<double> energies;
+    Config conf;
     
     if(argc == 1 ){
         help();
@@ -98,6 +99,20 @@ int main( int argc, char * argv[] )
             else{
                 throw std::invalid_argument("material field is missing");
                 }
+            if(j.count("config")>0){
+                auto e = j["config"];
+                if(e.is_string()){
+                    std::string cstr = e.get<std::string>();
+                    if(cstr=="atimav1.3"){
+                        conf.z_effective = z_eff_type::pierce_blann;
+                        cout<<"using config: Atima v1.3\n";
+                    }
+                    if(cstr=="atimav1.4"){
+                        conf.z_effective = z_eff_type::atima14;
+                        cout<<"using config: Atima v1.4\n";
+                    }
+                }
+            }
                 
         } // end of try 
         catch(...){
diff --git a/docs/catima_calculator.md b/docs/catima_calculator.md
new file mode 100644
index 0000000..1bf8163
--- /dev/null
+++ b/docs/catima_calculator.md
@@ -0,0 +1,135 @@
+Catima Caluclator
+================
+Catima Caluclator is a command line application and interface to the catime library.
+
+Usage
+-----
+The application is executed from the command line:
+
+```
+    catima_calculator config_file";
+```
+
+example
+```
+    catima_calculator c.json
+```
+
+Config File Format
+------------------
+The file must be a valid JSON formatted file.  
+
+The json file should contain the following keys: "projectile", "material", "energy"
+
+#### projectile
+The __projectile__ keywords are:
+  * array - 2 number array, 1st is mass number, 2nd is charge of the projectile
+
+examples:
+```
+    "projectile":[11.997,6],
+```
+
+#### material
+The __material__ keyword is array of object for multi layer material,
+or single object defining the material.
+The material object must contain __Z__ keyword defining proton number 
+of the projectile or the compound material id. 
+Optional material object keywords are:
+  * __Z__ - proton number or compunds id, mandatory
+  * __A__ - mass number of the material, if 0 or undefined elemental atomic weight is used
+  * __density__ - density in g/cm3, if 0 or undefined the tabulated density will be used.
+  * __thickness__ - material or layer thickness in g/cm2
+
+#### energy
+The __energy__ keyword can be 
+1.a number specifying the kinetic energy:
+```
+    "energy":"500.0"
+```
+
+2. array of numbers for multiple energies:
+```
+    "energy":[100,200,500,1000]
+```
+
+3. Object specifying minimum energy, maximum energy and energy step, to calculate multiple energies:
+```
+    "energy":{
+        "min": 100,
+        "max": 1000,
+        "step": 10
+    }
+```
+instead of "step" key the "num" can be specified for integer number of steps between min and max energy.
+
+#### config
+The calculation configuration can be change using __config__ keyword. If 
+not specified default will be used. The config keyword is expected to be one of the strings
+  * "atimav1.3" - for Atima v1.3 setting
+  * "atimav1.4" - for Atima v1.4 setting
+```
+"config":"atimav1.4"
+```
+
+
+
+Example Files
+-------------------
+```
+{
+"projectile":[11.99671, 6],
+"energy": 1000,
+"material":[{"A":12.0107,
+            "Z":6,
+            "thickness":1.0
+            },
+            {
+            "A":55.845,
+            "Z":26,
+            "density":7.8,
+            "thickness":0.05
+            }
+            ],
+"config":"atimav1.4"
+}
+```
+
+```
+{
+"projectile":[11.99671, 6],
+"energy":{
+    "min": 100,
+    "max": 1000,
+    "step": 100
+    },
+"material":[{"A":12.0107,
+            "Z":6,
+            "thickness":1.0
+            },
+            {
+            "A":55.845,
+            "Z":26,
+            "density":7.8,
+            "thickness":0.05
+            }
+            ]
+}
+```
+
+```
+{
+"projectile":[11.99671, 6],
+"energy":{
+    "min": 100,
+    "max": 1000,
+    "step": 100
+    },
+"material":{"A":12,
+            "Z":6,
+            "density":2.0,
+            "thickness":1.0
+            }
+}
+```
+