Feature: Add planewave parallization support for BPCG method

[Cstandardlib]

Linked Issue

Fix #3437

What's changed?

• Add MPI multicore planewave parallization support for BPCG method.

[Cstandardlib]

Currently, BPCG converges under MPI multi-core conditions, but there is a slight difference in precision compared to single-core, which requires further investigation.

Integrate test integrate/102_PW_BPCG will still run in serial mode, i.e. mpirun -np 1 $abacus.

[Cstandardlib]

Tests show that eigenvalues diverge at the very first round of iter:

• np = 4

 DONE(0.387236   SEC) : INIT SCF
eigenvalue[0] = -1.59241
eigenvalue[1] = -1.59117
eigenvalue[2] = -1.58078
eigenvalue[3] = -1.57916
eigenvalue[4] = -1.57533
eigenvalue[5] = -0.337989
eigenvalue[6] = -0.202191
eigenvalue[7] = -0.196922
eigenvalue[8] = -0.172316
eigenvalue[9] = -0.166048
eigenvalue[10] = -0.157684
eigenvalue[11] = 0.560756
eigenvalue[12] = 0.619775
eigenvalue[13] = 0.673029
eigenvalue[14] = 0.684267
eigenvalue[15] = 0.967494
eigenvalue[16] = 0.988857
eigenvalue[17] = 1.02778
eigenvalue[18] = 1.19561
eigenvalue[19] = 1.449
eigenvalue[20] = 1.48429
eigenvalue[21] = 1.48959
eigenvalue[22] = 1.55905
eigenvalue[23] = 1.57068

• np = 1

 DONE(0.385729   SEC) : INIT SCF
eigenvalue[0] = -1.5924
eigenvalue[1] = -1.59117
eigenvalue[2] = -1.58079
eigenvalue[3] = -1.57916
eigenvalue[4] = -1.57533
eigenvalue[5] = -0.337989
eigenvalue[6] = -0.202191
eigenvalue[7] = -0.196922
eigenvalue[8] = -0.172316
eigenvalue[9] = -0.166048
eigenvalue[10] = -0.157684
eigenvalue[11] = 0.560756
eigenvalue[12] = 0.619775
eigenvalue[13] = 0.673029
eigenvalue[14] = 0.684267
eigenvalue[15] = 0.96749
eigenvalue[16] = 0.988901
eigenvalue[17] = 1.02778
eigenvalue[18] = 1.19561
eigenvalue[19] = 1.44897
eigenvalue[20] = 1.48398
eigenvalue[21] = 1.49106
eigenvalue[22] = 1.55956
eigenvalue[23] = 1.5701

and errors accumulate as the iter goes.

[Cstandardlib]

The bug stems from the hPsi function.
See #5854 for details.

[Qianruipku]

Please also change "mpirun -np 1" to "mpirun -np 4" in Autotest.sh and update results.ref?

[Cstandardlib]

Output of mpirun -np 4 on test machine:

1: [ RUN      ] 102_PW_BPCG
1: [      OK  ]  etotref
1: [      OK  ]  etotperatomref
1: [WARNING   ]  totalforceref cal=5.19522000 ref=5.19483000 deviation=-0.00039000
1: [WARNING   ]  totalstressref cal=37241.49490600 ref=37241.45334600 deviation=-0.04156000
1: [      OK  ]  pointgroupref
1: [      OK  ]  spacegroupref
1: [      OK  ]  nksibzref

Update reference value in result.ref accordingly.