Fixed G16 confirmed specifications and alternate specification syntax

ccinput/packages/gaussian.py

@@ -124,6 +124,12 @@ def handle_specifications(self):
                 for option in options.split(","):
                     if option.strip() != "":
                         self.add_option(key, option)
+            elif spec.find("=") != -1:
+                try:
+                    key, option = spec.split("=")
+                except ValueError:
+                    raise InvalidParameter(f"Invalid specification: {spec}")
+                self.add_option(key, option)
             else:
                 self.add_option(spec, "")
 
@@ -371,7 +377,8 @@ def create_input_file(self):
             if cmd.lower() != "scrf":
                 spec_options = []
                 for o in options:
-                    print(o)
+                    if o.strip() == "":
+                        continue
                     if self.calc.type == CalcType.TS and o in [
                         "ts",
                         "NoEigenTest",
@@ -383,6 +390,7 @@ def create_input_file(self):
                     spec_options.append(o)
                 if len(spec_options) > 0:
                     spec_option_str = ", ".join(spec_options)
+
                     confirmed_spec = f"{cmd}({spec_option_str}) "
                     if cmd in self.KEYWORD_LIST:
                         self.confirmed_specifications = (

ccinput/tests/test_gaussian.py

@@ -2133,6 +2133,53 @@ def test_multiple_global_specification3(self):
         self.assertTrue(self.is_equivalent(REF, inp.input_file))
         self.assertEqual(inp.confirmed_specifications.strip(), "scf(tight, xqc)")
 
+    def test_alternate_syntax_specification(self):
+        params = {
+            "nproc": 8,
+            "mem": "10000MB",
+            "type": "Single-Point Energy",
+            "file": "Cl.xyz",
+            "software": "Gaussian",
+            "method": "M06-2X",
+            "basis_set": "Def2-SVP",
+            "charge": "-1",
+            "specifications": "SCF=Tight",
+        }
+
+        inp = self.generate_calculation(**params)
+
+        REF = """
+        %chk=calc.chk
+        %nproc=8
+        %mem=10000MB
+        #p sp M062X/Def2SVP scf(tight)
+
+        File created by ccinput
+
+        -1 1
+        Cl 0.0 0.0 0.0
+
+        """
+
+        self.assertTrue(self.is_equivalent(REF, inp.input_file))
+        self.assertEqual(inp.confirmed_specifications.strip(), "scf(tight)")
+
+    def test_alternate_syntax_specification_invalid(self):
+        params = {
+            "nproc": 8,
+            "mem": "10000MB",
+            "type": "Single-Point Energy",
+            "file": "Cl.xyz",
+            "software": "Gaussian",
+            "method": "M06-2X",
+            "basis_set": "Def2-SVP",
+            "charge": "-1",
+            "specifications": "SCF=Tight=2",
+        }
+
+        with self.assertRaises(InvalidParameter):
+            self.generate_calculation(**params)
+
     def test_cmd_specification(self):
         params = {
             "nproc": 8,