fix: reset LAMMPS minimization timesteps

Coding-Agent: Codex
Codex-Version: codex-cli 0.149.0
Model: gpt-5.6-sol
Reasoning-Effort: xhigh

Author: njzjz-bot

dpgen/auto_test/lib/lammps.py

@@ -252,8 +252,11 @@ def make_lammps_equi(
     if change_box:
         ret += "fix             1 all box/relax iso 0.0 \n"
         ret += "minimize        %e %e %d %d\n" % (etol, ftol, maxiter, maxeval)  # noqa: UP031
+        # Align dump and thermo output at the start of each minimization stage.
+        ret += "reset_timestep  0\n"
         ret += "fix             1 all box/relax aniso 0.0 \n"
         ret += "minimize        %e %e %d %d\n" % (etol, ftol, maxiter, maxeval)  # noqa: UP031
+        ret += "reset_timestep  0\n"
         ret += "fix             1 all box/relax tri 0.0 \n"
     ret += "minimize        %e %e %d %d\n" % (etol, ftol, maxiter, maxeval)  # noqa: UP031
     ret += "variable        N equal count(all)\n"

tests/auto_test/test_lammps.py

@@ -11,7 +11,7 @@
 
 from dpgen.auto_test.common_equi import make_equi, run_equi
 from dpgen.auto_test.Lammps import Lammps
-from dpgen.auto_test.lib.lammps import inter_deepmd
+from dpgen.auto_test.lib.lammps import inter_deepmd, make_lammps_equi
 
 from .context import setUpModule  # noqa: F401
 
@@ -94,6 +94,31 @@ def test_make_input_file(self):
         self.assertTrue(os.path.islink(os.path.join(abs_equi_path, "in.lammps")))
         self.assertTrue(os.path.isfile(os.path.join(abs_equi_path, "task.json")))
 
+    def test_make_lammps_equi_resets_successive_minimizations(self):
+        """Successive box relaxations should share aligned output timesteps."""
+        input_text = make_lammps_equi(
+            "conf.lmp",
+            {"Al": 0},
+            inter_deepmd,
+            {
+                "model_name": ["frozen_model.pb"],
+                "param_type": {"Al": 0},
+                "deepmd_version": "1.1.0",
+            },
+        )
+        lines = input_text.splitlines()
+        minimize_lines = [
+            index for index, line in enumerate(lines) if line.startswith("minimize")
+        ]
+        reset_lines = [
+            index
+            for index, line in enumerate(lines)
+            if line.startswith("reset_timestep")
+        ]
+
+        self.assertEqual(3, len(minimize_lines))
+        self.assertEqual([minimize_lines[0] + 1, minimize_lines[1] + 1], reset_lines)
+
     def test_forward_common_files(self):
         fc_files = ["in.lammps", "frozen_model.pb"]
         self.assertEqual(self.Lammps.forward_common_files(), fc_files)