Add a Si PW integration case for ks_solver ppcg

Author: cheerly-pku

tests/01_PW/818_PW_PPCG_Si/INPUT

@@ -0,0 +1,33 @@
+INPUT_PARAMETERS 
+#Parameters	(General)
+suffix            autotest
+pseudo_dir        ../../PP_ORB
+pw_seed           1
+
+gamma_only        0
+calculation       scf
+symmetry          1
+out_level         ie
+smearing_method   gaussian
+smearing_sigma    0.02
+
+#Parameters (3.PW)
+ecutwfc           40
+scf_thr           1e-6
+scf_nmax          50
+
+#Parameters (LCAO)
+basis_type        pw
+ks_solver         ppcg
+device            cpu
+nbands            6
+chg_extrap        second-order
+pw_diag_thr       0.00001
+pw_diag_ndim      4
+
+cal_force         1
+cal_stress        1
+
+mixing_type       broyden
+mixing_beta       0.4
+mixing_gg0        1.5

tests/01_PW/818_PW_PPCG_Si/KPT

@@ -0,0 +1,4 @@
+K_POINTS
+0
+Gamma
+2 2 2  0 0 0

tests/01_PW/818_PW_PPCG_Si/README

@@ -0,0 +1 @@
+pw basis for Si with ks_solver ppcg (projection preconditioned conjugate-gradient), multi k

tests/01_PW/818_PW_PPCG_Si/STRU

@@ -0,0 +1,19 @@
+ATOMIC_SPECIES
+Si 1.000 Si_dojo_nsoc.upf
+
+LATTICE_CONSTANT
+10.2
+
+LATTICE_VECTORS
+0.0 0.5 0.5
+0.5 0.0 0.5
+0.5 0.5 0.0
+
+ATOMIC_POSITIONS
+Direct
+
+Si
+0.0
+2
+0.00 0.00 0.00 0 0 0
+0.25 0.25 0.25 0 0 0

tests/01_PW/818_PW_PPCG_Si/result.ref

@@ -0,0 +1,8 @@
+etotref -227.6796308171406622
+etotperatomref -113.8398154086
+totalforceref 0.000000
+totalstressref 343.464036
+pointgroupref T_d
+spacegroupref O_h
+nksibzref 3
+totaltimeref 0.95

tests/01_PW/CASES_CPU.txt

@@ -133,3 +133,4 @@ scf_out_chg_tau
 815_PW_DFTU_S2_Z
 816_PW_DFTU_S4_XY
 817_PW_PPCG
+818_PW_PPCG_Si