PwBandsWorkChain: Move inputs to protocol

Several "default" inputs of the `PwBandsWorkChain` are set inside one of
the steps of the work chain, which:

1. Can be confusing for the user, since the expected inputs are not
there in the input files.
2. Can be frustrating for the user when a different value is desirable,
for a use case that may not immediately be obvious.
3. Means default values are specified _both_ in the work chain logic and
protocol, making it more difficult to get a clear overview of the input
parameters.

Here we move the specification of the default inputs to the protocol
file of the `PwBandsWorkChain` (`bands.yaml`).

Since the default protocol now correctly sets the calculation type to
`bands`, the `validate_inputs` validator of the `PwCalculation` will
raise a warning because a `parent_folder` has not been initially
provided. Hence, we set the `validate_inputs_base` validator for the
`pw` port of the `bands` namespace, as is also done for e.g. the
`nscf` of the `PdosWorkchain`.

Finally, we switch to using 2 spaces for the indentation of the protocol
YAML files to make them easier to read.

src/aiida_quantumespresso/workflows/protocols/core_hole_treatments.yaml

@@ -1,29 +1,29 @@
 default_inputs:
-    SYSTEM:
-        tot_charge: 1
+  SYSTEM:
+    tot_charge: 1
 default_treatment: full
 treatments:
-    full:
-        description: 'Core-hole treatment using a formal countercharge of +1, equivalent to removing one electron from the system.'
-    half:
-        description: 'Core-hole treatment using a formal countercharge of +0.5, equivalent to removing half an electron from the system.'
-        SYSTEM:
-            tot_charge: 0.5
-    xch_fixed:
-        description: 'Core-hole treatment which places the excited electron into the conduction band (fixed occupations).'
-        SYSTEM:
-            occupations: fixed
-            tot_charge: 0
-            nspin: 2
-            tot_magnetization: 1
-    xch_smear:
-        description: 'Core-hole treatment which places the excited electron into the conduction band (smeared occupations).'
-        SYSTEM:
-            occupations: smearing
-            tot_charge: 0
-            nspin: 2
-            starting_magnetization(1): 0
-    none:
-        description: 'Applies no core-hole treatment (overrides the default tot_charge and changes it to 0).'
-        SYSTEM:
-            tot_charge: 0
+  full:
+    description: 'Core-hole treatment using a formal countercharge of +1, equivalent to removing one electron from the system.'
+  half:
+    description: 'Core-hole treatment using a formal countercharge of +0.5, equivalent to removing half an electron from the system.'
+    SYSTEM:
+      tot_charge: 0.5
+  xch_fixed:
+    description: 'Core-hole treatment which places the excited electron into the conduction band (fixed occupations).'
+    SYSTEM:
+      occupations: fixed
+      tot_charge: 0
+      nspin: 2
+      tot_magnetization: 1
+  xch_smear:
+    description: 'Core-hole treatment which places the excited electron into the conduction band (smeared occupations).'
+    SYSTEM:
+      occupations: smearing
+      tot_charge: 0
+      nspin: 2
+      starting_magnetization(1): 0
+  none:
+    description: 'Applies no core-hole treatment (overrides the default tot_charge and changes it to 0).'
+    SYSTEM:
+      tot_charge: 0

src/aiida_quantumespresso/workflows/protocols/pdos.yaml

@@ -1,65 +1,65 @@
 default_inputs:
-    clean_workdir: True
-    scf:
-        pw:
-            parameters:
-                CONTROL:
-                    restart_mode: from_scratch
+  clean_workdir: True
+  scf:
+    pw:
+      parameters:
+        CONTROL:
+          restart_mode: from_scratch
+  nscf:
+    kpoints_distance: 0.10
+    pw:
+      parameters:
+        CONTROL:
+          calculation: nscf
+          restart_mode: from_scratch
+        SYSTEM:
+          occupations: tetrahedra
+          nosym: True
+  dos:
+    parameters:
+      DOS:
+        DeltaE: 0.02
+    metadata:
+      options:
+        resources:
+          num_machines: 1
+        max_wallclock_seconds: 43200  # Twelve hours
+        withmpi: True
+  projwfc:
+    parameters:
+      PROJWFC:
+        DeltaE: 0.02
+    metadata:
+      options:
+        resources:
+          num_machines: 1
+        max_wallclock_seconds: 43200  # Twelve hours
+        withmpi: True
+default_protocol: moderate
+protocols:
+  moderate:
+    description: 'Protocol to perform a projected density of states calculation at normal precision at moderate computational cost.'
+  precise:
+    description: 'Protocol to perform a projected density of states structure calculation at high precision at higher computational cost.'
+    dos:
+      parameters:
+        DOS:
+          DeltaE: 0.01
+    projwfc:
+      parameters:
+        PROJWFC:
+          DeltaE: 0.01
     nscf:
-        kpoints_distance: 0.10
-        pw:
-            parameters:
-                CONTROL:
-                    calculation: nscf
-                    restart_mode: from_scratch
-                SYSTEM:
-                    occupations: tetrahedra
-                    nosym: True
+      kpoints_distance: 0.05
+  fast:
+    description: 'Protocol to perform a projected density of states structure calculation at low precision at minimal computational cost for testing purposes.'
     dos:
-        parameters:
-            DOS:
-                DeltaE: 0.02
-        metadata:
-            options:
-                resources:
-                    num_machines: 1
-                max_wallclock_seconds: 43200  # Twelve hours
-                withmpi: True
+      parameters:
+        DOS:
+          DeltaE: 0.1
     projwfc:
-        parameters:
-            PROJWFC:
-                DeltaE: 0.02
-        metadata:
-            options:
-                resources:
-                    num_machines: 1
-                max_wallclock_seconds: 43200  # Twelve hours
-                withmpi: True
-default_protocol: moderate
-protocols:
-    moderate:
-        description: 'Protocol to perform a projected density of states calculation at normal precision at moderate computational cost.'
-    precise:
-        description: 'Protocol to perform a projected density of states structure calculation at high precision at higher computational cost.'
-        dos:
-            parameters:
-                DOS:
-                    DeltaE: 0.01
-        projwfc:
-            parameters:
-                PROJWFC:
-                    DeltaE: 0.01
-        nscf:
-            kpoints_distance: 0.05
-    fast:
-        description: 'Protocol to perform a projected density of states structure calculation at low precision at minimal computational cost for testing purposes.'
-        dos:
-            parameters:
-                DOS:
-                    DeltaE: 0.1
-        projwfc:
-            parameters:
-                PROJWFC:
-                    DeltaE: 0.1
-        nscf:
-            kpoints_distance: 0.5
+      parameters:
+        PROJWFC:
+          DeltaE: 0.1
+    nscf:
+      kpoints_distance: 0.5

src/aiida_quantumespresso/workflows/protocols/ph/base.yaml

@@ -1,36 +1,36 @@
 default_inputs:
-    clean_workdir: True
-    ph:
-        metadata:
-            options:
-                resources:
-                    num_machines: 1
-                max_wallclock_seconds: 43200  # Twelve hours
-                withmpi: True
-        parameters:
-            INPUTPH:
-                tr2_ph: 1.0e-18
-        qpoints:
-          - 3
-          - 3
-          - 3
+  clean_workdir: True
+  ph:
+    metadata:
+      options:
+        resources:
+          num_machines: 1
+        max_wallclock_seconds: 43200  # Twelve hours
+        withmpi: True
+    parameters:
+      INPUTPH:
+        tr2_ph: 1.0e-18
+    qpoints:
+      - 3
+      - 3
+      - 3
 default_protocol: moderate
 protocols:
-    moderate:
-        description: 'Protocol to perform the computation at normal precision at moderate computational cost.'
-    precise:
-        description: 'Protocol to perform the computation at high precision at higher computational cost.'
-        ph:
-            parameters:
-                INPUTPH:
-                    tr2_ph: 1.0e-20
-    fast:
-        description: 'Protocol to perform the computation at low precision at minimal computational cost for testing purposes.'
-        ph:
-            parameters:
-                INPUTPH:
-                    tr2_ph: 1.0e-16
-            qpoints:
-              - 2
-              - 2
-              - 2
+  moderate:
+    description: 'Protocol to perform the computation at normal precision at moderate computational cost.'
+  precise:
+    description: 'Protocol to perform the computation at high precision at higher computational cost.'
+    ph:
+      parameters:
+        INPUTPH:
+          tr2_ph: 1.0e-20
+  fast:
+    description: 'Protocol to perform the computation at low precision at minimal computational cost for testing purposes.'
+    ph:
+      parameters:
+        INPUTPH:
+          tr2_ph: 1.0e-16
+      qpoints:
+        - 2
+        - 2
+        - 2

src/aiida_quantumespresso/workflows/protocols/pw/bands.yaml

@@ -1,14 +1,28 @@
 default_inputs:
-    bands_kpoints_distance: 0.025
-    clean_workdir: True
-    nbands_factor: 3.0
+  bands_kpoints_distance: 0.025
+  clean_workdir: True
+  nbands_factor: 3.0
+  scf:
+    pw:
+      parameters:
+        CONTROL:
+          calculation: scf
+  bands:
+    pw:
+      parameters:
+        CONTROL:
+          calculation: bands
+        ELECTRONS:
+          diagonalization: paro
+          diago_full_acc: True
+
 default_protocol: moderate
 protocols:
-    moderate:
-        description: 'Protocol to perform a band structure calculation at normal precision at moderate computational cost.'
-    precise:
-        description: 'Protocol to perform a band structure calculation at high precision at higher computational cost.'
-        bands_kpoints_distance: 0.015
-    fast:
-        description: 'Protocol to perform a band structure calculation at low precision at minimal computational cost for testing purposes.'
-        bands_kpoints_distance: 0.1
+  moderate:
+    description: 'Protocol to perform a band structure calculation at normal precision at moderate computational cost.'
+  precise:
+    description: 'Protocol to perform a band structure calculation at high precision at higher computational cost.'
+    bands_kpoints_distance: 0.015
+  fast:
+    description: 'Protocol to perform a band structure calculation at low precision at minimal computational cost for testing purposes.'
+    bands_kpoints_distance: 0.1

src/aiida_quantumespresso/workflows/protocols/pw/base.yaml

@@ -1,54 +1,54 @@
 default_inputs:
-    clean_workdir: True
-    kpoints_distance: 0.15
-    kpoints_force_parity: False
-    meta_parameters:
-        conv_thr_per_atom: 0.2e-9
-        etot_conv_thr_per_atom: 1.e-5
-    pseudo_family: 'SSSP/1.2/PBEsol/efficiency'
-    pw:
-        metadata:
-            options:
-                resources:
-                    num_machines: 1
-                max_wallclock_seconds: 43200  # Twelve hours
-                withmpi: True
-        parameters:
-            CONTROL:
-                calculation: scf
-                forc_conv_thr: 1.e-4
-                tprnfor: True
-                tstress: True
-            SYSTEM:
-                nosym: False
-                occupations: smearing
-                smearing: cold
-                degauss: 0.01
-            ELECTRONS:
-                electron_maxstep: 80
-                mixing_beta: 0.4
+  clean_workdir: True
+  kpoints_distance: 0.15
+  kpoints_force_parity: False
+  meta_parameters:
+    conv_thr_per_atom: 0.2e-9
+    etot_conv_thr_per_atom: 1.e-5
+  pseudo_family: 'SSSP/1.2/PBEsol/efficiency'
+  pw:
+    metadata:
+      options:
+        resources:
+          num_machines: 1
+        max_wallclock_seconds: 43200  # Twelve hours
+        withmpi: True
+    parameters:
+      CONTROL:
+        calculation: scf
+        forc_conv_thr: 1.e-4
+        tprnfor: True
+        tstress: True
+      SYSTEM:
+        nosym: False
+        occupations: smearing
+        smearing: cold
+        degauss: 0.01
+      ELECTRONS:
+        electron_maxstep: 80
+        mixing_beta: 0.4
 default_protocol: moderate
 protocols:
-    moderate:
-        description: 'Protocol to perform the computation at normal precision at moderate computational cost.'
-    precise:
-        description: 'Protocol to perform the computation at high precision at higher computational cost.'
-        kpoints_distance: 0.10
-        meta_parameters:
-            conv_thr_per_atom: 0.1e-9
-            etot_conv_thr_per_atom: 0.5e-5
-        pseudo_family: 'SSSP/1.2/PBEsol/precision'
-        pw:
-            parameters:
-                CONTROL:
-                    forc_conv_thr: 0.5e-4
-    fast:
-        description: 'Protocol to perform the computation at low precision at minimal computational cost for testing purposes.'
-        kpoints_distance: 0.50
-        meta_parameters:
-            conv_thr_per_atom: 0.4e-9
-            etot_conv_thr_per_atom: 1.e-4
-        pw:
-            parameters:
-                CONTROL:
-                    forc_conv_thr: 1.e-3
+  moderate:
+    description: 'Protocol to perform the computation at normal precision at moderate computational cost.'
+  precise:
+    description: 'Protocol to perform the computation at high precision at higher computational cost.'
+    kpoints_distance: 0.10
+    meta_parameters:
+      conv_thr_per_atom: 0.1e-9
+      etot_conv_thr_per_atom: 0.5e-5
+    pseudo_family: 'SSSP/1.2/PBEsol/precision'
+    pw:
+      parameters:
+        CONTROL:
+          forc_conv_thr: 0.5e-4
+  fast:
+    description: 'Protocol to perform the computation at low precision at minimal computational cost for testing purposes.'
+    kpoints_distance: 0.50
+    meta_parameters:
+      conv_thr_per_atom: 0.4e-9
+      etot_conv_thr_per_atom: 1.e-4
+    pw:
+      parameters:
+        CONTROL:
+          forc_conv_thr: 1.e-3