From c9545ee03b7440b19422ed0c75493ec7f99ca73f Mon Sep 17 00:00:00 2001
From: Christoph Lehner <christoph@lhnr.de>
Date: Tue, 31 Oct 2023 17:15:34 +0100
Subject: [PATCH] fix edge cases

---
 lib/gpt/core/component.py |  2 ++
 lib/gpt/core/transform.py | 17 +++++++++--------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/lib/gpt/core/component.py b/lib/gpt/core/component.py
index a8e9cc27..10982499 100644
--- a/lib/gpt/core/component.py
+++ b/lib/gpt/core/component.py
@@ -23,6 +23,8 @@
 
 def _simple_map(operator, numpy_operator=None, extra_params={}):
     def _mat(first, second=None):
+        if isinstance(first, list):
+            return [_mat(x) for x in first]
         if second is not None:
             dst = first
             src = gpt.eval(second)
diff --git a/lib/gpt/core/transform.py b/lib/gpt/core/transform.py
index 39a7ab38..de9e7e5d 100644
--- a/lib/gpt/core/transform.py
+++ b/lib/gpt/core/transform.py
@@ -89,15 +89,16 @@ def norm2(l):
     l = gpt.util.to_list(l)
     l_lattices = [(i, l[i]) for i in range(len(l)) if isinstance(l[i], gpt.lattice)]
     l_tensors = [(i, l[i]) for i in range(len(l)) if isinstance(l[i], gpt.tensor)]
-    ip_l = (
-        l_lattices[0][1]
-        .grid.globalsum(
-            numpy.array([rank_inner_product(x, x) for i, x in l_lattices], dtype=numpy.complex128)
+    if len(l_lattices) > 0:
+        ip_l = (
+            l_lattices[0][1]
+            .grid.globalsum(
+                numpy.array([rank_inner_product(x, x) for i, x in l_lattices], dtype=numpy.complex128)
+            )
+            .real
         )
-        .real
-    )
-    ip_t = [x.norm2() for i, x in l_tensors]
-    ip = numpy.ndarray(dtype=numpy.complex128, shape=(len(l),))
+    ip_t = [x.norm2().real for i, x in l_tensors]
+    ip = numpy.ndarray(dtype=numpy.float64, shape=(len(l),))
     for i, j in enumerate(l_lattices):
         ip[j[0]] = ip_l[i]
     for i, j in enumerate(l_tensors):