Bug: Partial charge density and wavefunction ouput under PW basis is incorrect when kpar is on #6227
Description
Describe the bug
This feature was not implemented with k-point parallelization (kpar) in mind, so only the k-points on the main MPI process are computed.
The output files and charge grid integration results when kpar=1 (correct):
wf1s1k1.cube 1.000004681161136
wf1s1k2.cube 1.0000046811610666
wf1s1k3.cube 1.0000046811610543
wf1s1k4.cube 1.0000046811611043
wf1s2k1.cube 1.0000046811611278
wf1s2k2.cube 1.000004681161058
wf1s2k3.cube 1.000004681161077
wf1s2k4.cube 1.0000046811611274
wf2s1k1.cube 1.0000046811611147
wf2s1k2.cube 1.000004681161104
wf2s1k3.cube 1.000004681161086
wf2s1k4.cube 1.0000046811611165
wf2s2k1.cube 1.0000046811610603
wf2s2k2.cube 1.0000046811611158
wf2s2k3.cube 1.0000046811611083
wf2s2k4.cube 1.0000046811611125
when kpar=2:
wf1s1k1.cube 0.5000023405805791
wf1s1k2.cube 0.5000023405805298
wf1s2k1.cube 0.5000023405805598
wf1s2k2.cube 0.5000023405805604
wf2s1k1.cube 0.5000023405805543
wf2s1k2.cube 0.5000023405805655
wf2s2k1.cube 0.5000023405805597
wf2s2k2.cube 0.5000023405805555