Add Feature: XAS Plugin (#580)

Adds a plugin to calculate XANES spectra using the XspectraCrystalWorkChain of AiiDA-QE. The Setting panel allows users to simply select which element to calculate XAS for, as well as tuning the supercell size to be used in the calculation. This panel also provides the option to change the type of core-hole approximation between FCH (removing the excited electron with tot_charge = 1) and XCH (allowing the excited electron to occupy the conduction band. The result will display both the complete powder XAS for the input structure and the contributions from each symmetrically non-equivalent site. 


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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Xing Wang <xingwang1991@gmail.com>

setup.cfg

@@ -56,6 +56,7 @@ aiidalab_qe.properties =
     bands = aiidalab_qe.plugins.bands:bands
     pdos = aiidalab_qe.plugins.pdos:pdos
     electronic_structure = aiidalab_qe.plugins.electronic_structure:electronic_structure
+    xas = aiidalab_qe.plugins.xas:xas
 
 [aiidalab]
 title = Quantum ESPRESSO

src/aiidalab_qe/plugins/xas/__init__.py

@@ -0,0 +1,31 @@
+from importlib import resources
+
+import yaml
+from aiidalab_widgets_base import ComputationalResourcesWidget
+
+from aiidalab_qe.common.panel import OutlinePanel
+from aiidalab_qe.plugins import xas as xas_folder
+
+from .result import Result
+from .setting import Setting
+from .workchain import workchain_and_builder
+
+PSEUDO_TOC = yaml.safe_load(resources.read_text(xas_folder, "pseudo_toc.yaml"))
+
+
+class XasOutline(OutlinePanel):
+    title = "X-ray absorption spectroscopy (XAS)"
+    help = """"""
+
+
+xs_code = ComputationalResourcesWidget(
+    description="xspectra.x", default_calc_job_plugin="quantumespresso.xspectra"
+)
+
+xas = {
+    "outline": XasOutline,
+    "code": {"xspectra": xs_code},
+    "setting": Setting,
+    "result": Result,
+    "workchain": workchain_and_builder,
+}

src/aiidalab_qe/plugins/xas/pseudo_toc.yaml

@@ -0,0 +1,26 @@
+---
+xas_xch_elements: [C, Li]
+pseudos:
+    pbe:
+        gipaw_pseudos:
+            C: C.pbe-n-kjgipaw_psl.1.0.0.UPF
+            Cu: Cu.pbe-n-van_gipaw.UPF
+            F: F.pbe-gipaw_kj_no_hole.UPF
+            Li: Li.pbe-s-rrkjus-gipaw.UPF
+            O: O.pbe-n-kjpaw_gipaw.UPF
+            Si: Si.pbe-van_gipaw.UPF
+        core_wavefunction_data:
+            C: C.pbe-n-kjgipaw_psl.1.0.0.dat
+            Cu: Cu.pbe-n-van_gipaw.dat
+            F: F.pbe-gipaw_kj_no_hole.dat
+            Li: Li.pbe-s-rrkjus-gipaw.dat
+            O: O.pbe-n-kjpaw_gipaw.dat
+            Si: Si.pbe-van_gipaw.dat
+        core_hole_pseudos:
+            1s:
+                C: C.star1s.pbe-n-kjgipaw_psl.1.0.0.UPF
+                Cu: Cu.star1s-pbe-n-van_gipaw.UPF
+                F: F.star1s-pbe-gipaw_kj.UPF
+                Li: Li.star1s-pbe-s-rrkjus-gipaw-test_2.UPF
+                O: O.star1s.pbe-n-kjpaw_gipaw.UPF
+                Si: Si.star1s-pbe-van_gipaw.UPF