From 1659eda8f309db9a5e10e1ba6eea55a2ef7a91c2 Mon Sep 17 00:00:00 2001
From: Edan Bainglass <edan.bainglass@gmail.com>
Date: Thu, 16 Jan 2025 16:09:01 +0000
Subject: [PATCH] Add guards on null active eigenvalues

---
 .../configuration/advanced/hubbard/hubbard.py |  6 ++++--
 .../configuration/advanced/hubbard/model.py   | 19 +++++++++++--------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/src/aiidalab_qe/app/configuration/advanced/hubbard/hubbard.py b/src/aiidalab_qe/app/configuration/advanced/hubbard/hubbard.py
index 9170e9e81..b7dce95a1 100644
--- a/src/aiidalab_qe/app/configuration/advanced/hubbard/hubbard.py
+++ b/src/aiidalab_qe/app/configuration/advanced/hubbard/hubbard.py
@@ -39,10 +39,12 @@ def render(self):
         )
 
         self.eigenvalues_help = ipw.HTML("""
-            <div style="line-height: 1.4; margin-bottom: 5px;">
+            <div style="line-height: 1.4; margin: 10px 0 5px;">
                 For transition metals and lanthanoids, the starting eigenvalues can be defined (magnetic calculation).
                 <br>
-                It is useful to suggest the desired orbital occupations when the default choice takes another path.
+                It is useful to suggest the desired orbital occupations  when the default choice takes another path.
+                <br>
+                To do so, tick the checkbox below and set the desired eigenvalues to a value other than -1 (unset).
             </div>
         """)
         self.define_eigenvalues_checkbox = ipw.Checkbox(
diff --git a/src/aiidalab_qe/app/configuration/advanced/hubbard/model.py b/src/aiidalab_qe/app/configuration/advanced/hubbard/model.py
index 12672457e..7d9768816 100644
--- a/src/aiidalab_qe/app/configuration/advanced/hubbard/model.py
+++ b/src/aiidalab_qe/app/configuration/advanced/hubbard/model.py
@@ -66,15 +66,18 @@ def update(self, specific=""):  # noqa: ARG002
             self.needs_eigenvalues_widget = len(self.applicable_kind_names) > 0
 
     def get_active_eigenvalues(self):
-        active_eigenvalues = [
-            orbital_eigenvalue
-            for element_eigenvalues in self.eigenvalues
-            for spin_row in element_eigenvalues
-            for orbital_eigenvalue in spin_row
-            if orbital_eigenvalue[-1] != -1
-        ]
+        if not (
+            active_eigenvalues := [
+                orbital_eigenvalue
+                for element_eigenvalues in self.eigenvalues
+                for spin_row in element_eigenvalues
+                for orbital_eigenvalue in spin_row
+                if orbital_eigenvalue[-1] != -1
+            ]
+        ):
+            return []
         eigenvalues_array = np.array(active_eigenvalues, dtype=object)
-        new_shape = (np.prod(eigenvalues_array.shape[:-1]), 4)
+        new_shape = (int(np.prod(eigenvalues_array.shape[:-1])), 4)
         return eigenvalues_array.reshape(new_shape).tolist()
 
     def set_active_eigenvalues(self, eigenvalues: list):