diff --git a/source/module_relax/relax_new/line_search.cpp b/source/module_relax/relax_new/line_search.cpp
index 27772b4d10..fbe27f0f1c 100644
--- a/source/module_relax/relax_new/line_search.cpp
+++ b/source/module_relax/relax_new/line_search.cpp
@@ -12,7 +12,8 @@ bool Line_Search::line_search(
     double & xnew,  //the next point that we want to try
     const double conv_thr)
 {
-    if(restart) ls_step = 0;
+    if(restart) { ls_step = 0;
+}
 
     if(ls_step == 0) //first point: make a trial step into trial direction
     {
@@ -105,7 +106,8 @@ bool Line_Search::third_order(
         }
 
         dmoveh = -fa/(fab-fa)/2.0;
-        if(dmoveh<0) dmoveh = 4.0;
+        if(dmoveh<0) { dmoveh = 4.0;
+}
 
         if(dmove > 2.0*dmoveh || dmoveh > 2.0*dmove ||
             (fa*fb > 0 && dmove < 1.0) ||
@@ -115,11 +117,13 @@ bool Line_Search::third_order(
         }
     } //end anharmonic case
 
-    if(dmove > 4.0) dmove = 4.0;
+    if(dmove > 4.0) { dmove = 4.0;
+}
     xnew  = dmove +xa;
 
     double dy = (fb+(fab-fb)/(xa-xb)*(dmove-xb))*(dmove-xb);
-    if(std::abs(dy)<conv_thr) return true;
+    if(std::abs(dy)<conv_thr) { return true;
+}
 
     ls_step ++;
     return false;
@@ -140,7 +144,8 @@ void Line_Search::init_brent(
         xb = x;
         yb = y;
         fb = f;
-        if(fa*fb>0) bracked = false;
+        if(fa*fb>0) { bracked = false;
+}
         fstart = fa;
     }
     else // x < b
@@ -201,7 +206,7 @@ bool Line_Search::brent(
 {
     ls_step ++;
 
-    double xd,xe,xm;
+    double xd = 0.0,xe = 0.0 ,xm = 0.0;
     // if no zero is between xa and xb
     if(!bracked)
     {
@@ -239,7 +244,8 @@ bool Line_Search::brent(
                 p=s*(2.0*xm*qq*(qq-r)-(xb-xa)*(r-1.0));
                 qq=(qq-1.0)*(r-1.0)*(s-1.0);
             }
-            if(p>0.0) qq=-qq;
+            if(p>0.0) { qq=-qq;
+}
             p = std::abs(p);
 
             if( p < std::min(2.0*(xb-xa)*qq-std::abs(tol1*qq) , std::abs(xe*qq)/2.0) )
@@ -277,7 +283,8 @@ bool Line_Search::brent(
         }
 
         xnew = xb;
-        if(std::abs(dy)<conv_thr) return true;
+        if(std::abs(dy)<conv_thr) { return true;
+}
         if(ls_step == 4) //I'm not sure if this is a good choice, but the idea is there should not be so many line search steps
                          //I feel if the line search does not converge, we'd better change the direction and restart line search
         {
@@ -336,7 +343,8 @@ bool Line_Search::brent(
                 p=s*(2.0*xm*qq*(qq-r)-(xb-xa)*(r-1.0));
                 qq=(qq-1.0)*(r-1.0)*(s-1.0);
             }
-            if(p>0.0) qq=-qq;
+            if(p>0.0) { qq=-qq;
+}
             p = std::abs(p);
 
             if(2.0*p < std::min( 3.0*xm*qq-std::abs(tol1*qq), std::abs(xe*qq) ) )
@@ -380,7 +388,8 @@ bool Line_Search::brent(
         }
 
         xnew = xb;
-        if(std::abs(dy)<conv_thr) return true;
+        if(std::abs(dy)<conv_thr) { return true;
+}
         if(ls_step == 4)
         {
             GlobalV::ofs_running << "Too many Brent steps, let's do next CG step" << std::endl;
@@ -389,4 +398,4 @@ bool Line_Search::brent(
         }
         return false;
     }//end ibrack
-}
\ No newline at end of file
+}