Feat: Add DeepMD MLFF support

tests/forcefields/conftest.py

@@ -2,9 +2,12 @@
 
 from typing import TYPE_CHECKING
 
+import pytest
+import requests
 import torch
 
 if TYPE_CHECKING:
+    from pathlib import Path
     from typing import Any
 
 
@@ -13,3 +16,16 @@ def pytest_runtest_setup(item: Any) -> None:
     torch.set_default_dtype(torch.float32)
     # For consistent performance across hardware, explicitly set device to CPU
     torch.set_default_device("cpu")
+
+
+@pytest.fixture(scope="session", autouse=True)
+def download_deepmd_pretrained_model(test_dir: Path) -> None:
+    # Download DeepMD pretrained model from GitHub
+    file_url = "https://raw.github.com/sliutheorygroup/UniPero/main/model/graph.pb"
+    local_path = test_dir / "forcefields" / "deepmd" / "graph.pb"
+    response = requests.get(file_url, timeout=10)
+    if response.status_code == 200:
+        with open(local_path, "wb") as file:
+            file.write(response.content)
+    else:
+        raise requests.RequestException(f"Failed to download: {file_url}")

tests/forcefields/test_jobs.py

@@ -550,7 +550,7 @@ def test_deepmd_static_maker(sr_ti_o3_structure: Structure, test_dir: Path):
     # run the flow or job and ensure that it finished running successfully
     responses = run_locally(job, ensure_success=True)
 
-    # validation the outputs of the job
+    # validate the outputs of the job
     output1 = responses[job.uuid][1].output
     assert isinstance(output1, ForceFieldTaskDocument)
     assert output1.output.energy == approx(-3723.09868, rel=1e-4)
@@ -584,7 +584,7 @@ def test_deepmd_relax_maker(
     # run the flow or job and ensure that it finished running successfully
     responses = run_locally(job, ensure_success=True)
 
-    # validation the outputs of the job
+    # validate the outputs of the job
     output1 = responses[job.uuid][1].output
     assert isinstance(output1, ForceFieldTaskDocument)
     if relax_cell: