Updated the revise_lmp_input_dump function. (#1137)

Added the `model_devi_merge_traj` parameter to allow the merging of
trajectories into one file using the lmp_input template.

---------

Signed-off-by: Pan Xiang <panxiang126@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

dpgen/generator/run.py

@@ -921,12 +921,19 @@ def revise_lmp_input_model(lmp_lines, task_model_list, trj_freq, deepmd_version=
     return lmp_lines
 
 
-def revise_lmp_input_dump(lmp_lines, trj_freq):
+def revise_lmp_input_dump(lmp_lines, trj_freq, model_devi_merge_traj=False):
     idx = find_only_one_key(lmp_lines, ["dump", "dpgen_dump"])
-    lmp_lines[idx] = (
-        "dump            dpgen_dump all custom %d traj/*.lammpstrj id type x y z\n"
-        % trj_freq
-    )
+    if model_devi_merge_traj:
+        lmp_lines[idx] = (
+            "dump            dpgen_dump all custom %d    all.lammpstrj id type x y z\n"
+            % trj_freq
+        )
+    else:
+        lmp_lines[idx] = (
+            "dump            dpgen_dump all custom %d traj/*.lammpstrj id type x y z\n"
+            % trj_freq
+        )
+
     return lmp_lines
 
 
@@ -1317,7 +1324,9 @@ def _make_model_devi_revmat(iter_index, jdata, mdata, conf_systems):
                         deepmd_version=deepmd_version,
                     )
 
-                lmp_lines = revise_lmp_input_dump(lmp_lines, trj_freq)
+                lmp_lines = revise_lmp_input_dump(
+                    lmp_lines, trj_freq, model_devi_merge_traj
+                )
                 lmp_lines = revise_by_keys(
                     lmp_lines,
                     total_rev_keys[:total_num_lmp],