change input parameters

Author: Fei Yang

source/source_io/module_parameter/input_parameter.h

@@ -154,7 +154,7 @@ struct Input_para
 
     // ==============   #Parameters (4.Relaxation) ===========================
     std::string relax_method = "cg"; ///< methods to move_ion: sd, bfgs, cg...
-    RelaxMethodParam relax_method_param;
+    RelaxMethodParam relax_method_param={"cg","1"};
     bool relax_new = true;
     bool relax = false; ///< allow relaxation along the specific direction
     double relax_scale_force = 0.5;

source/source_io/read_input_item_relax.cpp

@@ -14,13 +14,7 @@ void ReadInput::item_relax()
         item.annotation = "cg; bfgs; sd; cg; cg_bfgs;";
         read_sync_string(input.relax_method);
         item.read_value = [](const Input_Item& item, Parameter& para) {
-        if(item.get_size()==0)
-        {
-            para.input.relax_method_param.method="cg";
-            para.input.relax_method = para.input.relax_method_param.method;
-            para.input.relax_method_param.param = "1"; 
-        }
-        else if(item.get_size()==1)
+        if(item.get_size()==1)
         {
             para.input.relax_method_param.method=item.str_values[0];
             para.input.relax_method = para.input.relax_method_param.method;
@@ -33,7 +27,7 @@ void ReadInput::item_relax()
             para.input.relax_method_param.param = item.str_values[1]; 
         }
         };
-        item.check_value = [](const Input_Item& item, const Parameter& para) {
+        item.check_value = [](const Input_Item& item, const Parameter& para) {          
         const std::vector<std::string> relax_methods = {"cg", "sd", "cg_bfgs","bfgs","lbfgs"};
         if (std::find(relax_methods.begin(), relax_methods.end(), para.input.relax_method_param.method) == relax_methods.end()) {
             const std::string warningstr = nofound_str(relax_methods, "relax_method");