Add test of phono3py.load that reads displacements

phono3py/api_phono3py.py

@@ -81,7 +81,7 @@ from phono3py.conductivity.rta import get_thermal_conductivity_RTA
 from phono3py.interface.fc_calculator import get_fc3
 from phono3py.interface.phono3py_yaml import Phono3pyYaml
 from phono3py.phonon.grid import BZGrid
-from phono3py.phonon3.dataset import get_displacements_and_forces_fc3
+from phono3py.phonon3.dataset import forces_in_dataset, get_displacements_and_forces_fc3
 from phono3py.phonon3.displacement_fc3 import (
     direction_to_displacement,
     get_third_order_displacements,
@@ -866,7 +866,7 @@ class Phono3py:
                 for disp2 in disp1["second_atoms"]:
                     displacements[i, disp2["number"]] = disp2["displacement"]
                     i += 1
-        elif "forces" in dataset or "displacements" in dataset:
+        elif "displacements" in dataset:
             displacements = dataset["displacements"]
         else:
             raise RuntimeError("displacement dataset has wrong format.")
@@ -2546,6 +2546,11 @@ class Phono3py:
         Return None if tagert data is not found rather than raising exception.
 
         """
+        if self._dataset is None:
+            return None
+        if not forces_in_dataset(self._dataset):
+            return None
+
         if target in self._dataset:  # type-2
             return self._dataset[target]
         elif "first_atoms" in self._dataset:  # type-1

phono3py/cui/create_force_constants.py

@@ -68,6 +68,7 @@ from phono3py.file_IO import (
 )
 from phono3py.interface.fc_calculator import extract_fc2_fc3_calculators
 from phono3py.interface.phono3py_yaml import Phono3pyYaml
+from phono3py.phonon3.dataset import forces_in_dataset
 from phono3py.phonon3.fc3 import (
     set_permutation_symmetry_fc3,
     set_translational_invariance_fc3,
@@ -316,22 +317,6 @@ def parse_forces(
     return dataset
 
 
-def forces_in_dataset(dataset: dict) -> bool:
-    """Return whether forces in dataset or not."""
-    if dataset is None:
-        return False
-    return "forces" in dataset or (
-        "first_atoms" in dataset and "forces" in dataset["first_atoms"][0]
-    )
-
-
-def displacements_in_dataset(dataset: Optional[dict]) -> bool:
-    """Return whether displacements in dataset or not."""
-    if dataset is None:
-        return False
-    return "displacements" in dataset or "first_atoms" in dataset
-
-
 def get_fc_calculator_params(settings, log_level=0):
     """Return fc_calculator and fc_calculator_params from settings."""
     fc_calculator = None

phono3py/cui/load.py

@@ -49,13 +49,13 @@ from phonopy.structure.cells import determinant
 
 from phono3py import Phono3py
 from phono3py.cui.create_force_constants import (
-    forces_in_dataset,
     parse_forces,
     run_pypolymlp_to_compute_forces,
 )
 from phono3py.file_IO import read_fc2_from_hdf5, read_fc3_from_hdf5
 from phono3py.interface.fc_calculator import extract_fc2_fc3_calculators
 from phono3py.interface.phono3py_yaml import Phono3pyYaml
+from phono3py.phonon3.dataset import forces_in_dataset
 from phono3py.phonon3.fc3 import show_drift_fc3
 
 

phono3py/phonon3/dataset.py

@@ -34,6 +34,8 @@
 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
+from typing import Optional
+
 import numpy as np
 
 
@@ -94,3 +96,12 @@ def get_displacements_and_forces_fc3(disp_dataset):
         return disp_dataset["displacements"], disp_dataset["forces"]
     else:
         raise RuntimeError("disp_dataset doesn't contain correct information.")
+
+
+def forces_in_dataset(dataset: Optional[dict]) -> bool:
+    """Return whether forces in dataset or not."""
+    if dataset is None:
+        return False
+    return "forces" in dataset or (
+        "first_atoms" in dataset and "forces" in dataset["first_atoms"][0]
+    )

test/conftest.py

@@ -69,6 +69,22 @@ def si_pbesol(request) -> Phono3py:
     )
 
 
+@pytest.fixture(scope="session")
+def si_pbesol_without_forcesets(request) -> Phono3py:
+    """Return Phono3py instance of Si 2x2x2 without force sets.
+
+    * with symmetry
+
+    """
+    yaml_filename = cwd / "phono3py_si_pbesol.yaml"
+    enable_v2 = request.config.getoption("--v2")
+    return phono3py.load(
+        yaml_filename,
+        make_r0_average=not enable_v2,
+        log_level=1,
+    )
+
+
 @pytest.fixture(scope="session")
 def si_pbesol_grg(request) -> Phono3py:
     """Return Phono3py instance of Si 2x2x2.

test/cui/test_phono3py_load.py

@@ -0,0 +1,18 @@
+"""Tests of Phono3py load."""
+
+from __future__ import annotations
+
+from phono3py import Phono3py
+
+
+def test_phono3py_load(si_pbesol_without_forcesets: Phono3py):
+    """Test phono3py.load.
+
+    Check phono3py.load can read displacements from phono3py_disp.yaml like file that
+    doesn't contain forces.
+
+    """
+    ph3 = si_pbesol_without_forcesets
+    assert ph3.dataset is not None
+    assert ph3.displacements.shape == (111, 64, 3)
+    assert ph3.forces is None

test/cui/test_phono3py_load_script.py

@@ -1,4 +1,4 @@
-"""Tests of Phono3py API."""
+"""Tests of phono3py-load script."""
 
 from __future__ import annotations