added missing info to vacuum

src/scgenerator/data/materials.toml

@@ -11,7 +11,9 @@
 B = [1.03961212, 0.231792344, 1.01046945]
 C = [6.00069867e-15, 2.00179144e-14, 1.03560653e-10]
 kind = 1
-    reference = ["SCHOTT Zemax catalog 2017-01-20b (obtained from http://www.schott.com)"]
+reference = [
+    "SCHOTT Zemax catalog 2017-01-20b (obtained from http://www.schott.com)",
+]
 
 [e7.sellmeier]
 B = [0.0, 7.2e-15, 3e-28]
@@ -22,7 +24,14 @@
 ]
 
 [d-zlaf52la.sellmeier]
-    B         = [-8.48750283e9, 3.1753525, 3.71301651e-14, -1.09609062e-27, 2.4418582e-40, -8.94583294e-54]
+B = [
+    -8.48750283e9,
+    3.1753525,
+    3.71301651e-14,
+    -1.09609062e-27,
+    2.4418582e-40,
+    -8.94583294e-54,
+]
 C = []
 kind = 3
 reference = ["CDGM Zemax catalog 2017-09 (obtained from http://www.cdgmgd.com)"]
@@ -248,6 +257,7 @@
 [vacuum]
 a = 0
 atomic_mass = 0
+atomic_number = 1
 b = 0
 
 [vacuum.sellmeier]