feat: support assigning ncpus for qmcalc (#216)

Fix #196.

---------

Signed-off-by: Jinzhe Zeng <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

mddatasetbuilder/qmcalc.py

@@ -2,18 +2,21 @@
 
 import argparse
 import os
+from typing import Optional
 
 from gaussianrunner import GaussianRunner
 
 
-def qmcalc(gjfdir, command="g16"):
+def qmcalc(gjfdir, command="g16", cpu_num: Optional[int] = None):
     """QM Calculation."""
     gjflist = [
         os.path.join(gjfdir, filename)
         for filename in os.listdir(gjfdir)
         if filename.endswith(".gjf")
     ]
-    GaussianRunner(command=command).runGaussianInParallel("GJF", gjflist)
+    GaussianRunner(command=command, cpu_num=cpu_num).runGaussianInParallel(
+        "GJF", gjflist
+    )
 
 
 def _commandline():
@@ -22,5 +25,11 @@ def _commandline():
     parser.add_argument(
         "-c", "--command", help="Gaussian command, default is g16", default="g16"
     )
+    parser.add_argument(
+        "-n",
+        "--ncpus",
+        help="Number of CPU cores used, if not set, all CPU cores are used",
+        default=None,
+    )
     args = parser.parse_args()
     qmcalc(gjfdir=args.dir, command=args.command)