[Work in progress] LNOCC

pyscf/lib/CMakeLists.txt

@@ -188,6 +188,15 @@ set_target_properties (clib_dsrg PROPERTIES
     LIBRARY_OUTPUT_DIRECTORY ${PROJECT_SOURCE_DIR}
     OUTPUT_NAME "dsrg")
 
+# Build the LNO library
+set (LNO_SOURCE_FILES "lno/ccsd_t.c")
+add_library (clib_lno SHARED ${LNO_SOURCE_FILES})
+target_link_libraries (clib_lno cc ao2mo cvhf np_helper ${BLAS_LIBRARIES} ${OPENMP_C_PROPERTIES})
+set_target_properties (clib_lno PROPERTIES
+    CLEAN_DIRECT_OUTPUT 1
+    LIBRARY_OUTPUT_DIRECTORY ${PROJECT_SOURCE_DIR}
+    OUTPUT_NAME "lno")
+
 # Build the CSFstring shared library
 set (CSF_SOURCE_FILES "csf/csfstring.c")
 add_library (clib_csf SHARED ${CSF_SOURCE_FILES})

pyscf/lno/__init__.py

@@ -0,0 +1,25 @@
+# Copyright 2014-2025 The PySCF Developers. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Hong-Zhou Ye
+#          Chenghan Li
+#          Xing Zhang
+#
+
+"""
+Local Natural Orbital methods
+"""
+from .lno import LNO
+from .lnoccsd import LNOCCSD, LNOCCSD_T
+from .ulnoccsd import ULNOCCSD, ULNOCCSD_T