From ca559c790c9d8737040c5e45597c9ff2784a2114 Mon Sep 17 00:00:00 2001
From: "Joey@macstudio" <johuang@aligntech.com>
Date: Sat, 11 Jul 2026 23:14:54 +0800
Subject: [PATCH] Use HayWadt ECP for ORCA LANL2DZ

---
 ccinput/constants.py       |  1 +
 ccinput/tests/test_orca.py | 31 +++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/ccinput/constants.py b/ccinput/constants.py
index 9f68268..450e8e9 100644
--- a/ccinput/constants.py
+++ b/ccinput/constants.py
@@ -2084,6 +2084,7 @@ class CalcType(Enum):
         "lanl08": "LANL08",
         "lanl08f": "LANL08(f)",
         "lanl2dz": "LANL2DZ",
+        "lanl2dzecp": "HayWadt",
         "lanl2tz": "LANL2TZ",
         "lanl2tzf": "LANL2TZ(f)",
         "sapporodzp2012": "Sapporo-DZP-2012",
diff --git a/ccinput/tests/test_orca.py b/ccinput/tests/test_orca.py
index 8f586f4..6f70709 100644
--- a/ccinput/tests/test_orca.py
+++ b/ccinput/tests/test_orca.py
@@ -1497,6 +1497,37 @@ def test_opt_DFT_custom_bs_ecp(self):
 
         self.assertTrue(self.is_equivalent(REF, inp.input_file))
 
+    def test_sp_DFT_custom_lanl2dz_ecp(self):
+        params = {
+            "nproc": 8,
+            "type": "Single-Point Energy",
+            "file": "AuI.xyz",
+            "software": "ORCA",
+            "method": "M06",
+            "basis_set": "6-31G",
+            "custom_basis_sets": "Au=LANL2DZ;",
+        }
+
+        inp = self.generate_calculation(**params)
+
+        REF = """
+        !SP M06 6-31G
+        *xyz 0 1
+        Au  -9.27600  -1.06330   0.00000
+        I   -6.60600  -1.06330   0.00000
+        *
+        %basis
+        NewGTO Au "LANL2DZ" end
+        NewECP Au "HayWadt" end
+        end
+        %pal
+        nprocs 8
+        end
+        %MaxCore 125
+        """
+
+        self.assertTrue(self.is_equivalent(REF, inp.input_file))
+
     def test_opt_DFT_two_custom_bs_ecp(self):
         params = {
             "nproc": 8,