fix bug when nproc > nz of scan

Author: Qianruipku

source/module_hamilt/ks_pw/meta_pw.cpp

@@ -65,11 +65,13 @@ void Meta<OperatorPW>::act
             }
 
             wfcpw->recip2real(porter, porter, ik);
-
-            const double* pvk = &(this->vk[0](current_spin, 0));
-            for (int ir = 0; ir < this->vk->nc; ir++)
+            if(this->vk->nc != 0)
             {
-                porter[ir] *= pvk[ir];
+                const double* pvk = &(this->vk[0](current_spin, 0));
+                for (int ir = 0; ir < this->vk->nc; ir++)
+                {
+                    porter[ir] *= pvk[ir];
+                }
             }
             wfcpw->real2recip(porter, porter, ik);
 

tests/integrate/101_PW_15_lowz/INPUT

@@ -7,19 +7,20 @@ nbands			6
 symmetry		1
 pseudo_dir      ../tools/PP_ORB/
 pseudo_type     upf201
+dft_functional  scan
 
 #Parameters (2.Iteration)
 ecutwfc			20
 scf_thr				1e-9
-scf_nmax			1
+scf_nmax			2
 
 
 #Parameters (3.Basis)
 basis_type		pw
 
 #Parameters (4.Smearing)
 smearing_method		gauss
-smearing_sigma			0.002
+smearing_sigma		0.002
 
 #Parameters (5.Mixing)
 mixing_type		pulay

tests/integrate/101_PW_15_lowz/result.ref

@@ -1,3 +1,3 @@
-etotref -1.407077993281502
-etotperatomref -0.7035389966
-totaltimeref 0.15155
+etotref -0.03063241935806423
+etotperatomref -0.0153162097
+totaltimeref