Fix : the tau_th judgement in v_xc_meta (#1532)

Author: wenfei-li

source/module_xc/xc_functional_vxc.cpp

@@ -511,7 +511,7 @@ tuple<double,double,ModuleBase::matrix,ModuleBase::matrix> XC_Functional::v_xc_m
     {
         for( size_t ir=0; ir!=nrxx; ++ir )
         {
-            if ( rho[ir]<rho_th || sqrt(abs(sigma[ir]))<grho_th || abs(kin_r[ir]<tau_th))
+            if ( rho[ir]<rho_th || sqrt(abs(sigma[ir]))<grho_th || abs(kin_r[ir])<tau_th)
             {
                 sgn[ir] = 0.0;
             }
@@ -521,9 +521,9 @@ tuple<double,double,ModuleBase::matrix,ModuleBase::matrix> XC_Functional::v_xc_m
     {
         for( size_t ir=0; ir!=nrxx; ++ir )
         {
-            if ( rho[ir*2]<rho_th || sqrt(abs(sigma[ir*3]))<grho_th || abs(kin_r[ir*2]<tau_th))
+            if ( rho[ir*2]<rho_th || sqrt(abs(sigma[ir*3]))<grho_th || abs(kin_r[ir*2])<tau_th)
                 sgn[ir*2] = 0.0;
-            if ( rho[ir*2+1]<rho_th || sqrt(abs(sigma[ir*3+2]))<grho_th || abs(kin_r[ir*2+1]<tau_th))
+            if ( rho[ir*2+1]<rho_th || sqrt(abs(sigma[ir*3+2]))<grho_th || abs(kin_r[ir*2+1])<tau_th)
                 sgn[ir*2+1] = 0.0;
         }
     }
@@ -650,4 +650,4 @@ tuple<double,double,ModuleBase::matrix,ModuleBase::matrix> XC_Functional::v_xc_m
 
 }
 
-#endif	//ifdef USE_LIBXC
+#endif	//ifdef USE_LIBXC