Varied and semi-sprited atmos markers (#4944)

Content.Shared/Atmos/Atmospherics.cs

@@ -26,6 +26,12 @@ namespace Content.Shared.Atmos
         /// </summary>
         public const float OneAtmosphere = 101.325f;
 
+        /// <summary>
+        ///     Maximum external pressure (in kPA) a gas miner will, by default, output to.
+        ///     This is used to initialize roundstart atmos rooms.
+        /// </summary>
+        public const float GasMinerDefaultMaxExternalPressure = 6500f;
+
         /// <summary>
         ///     -270.3ºC in K. CMB stands for Cosmic Microwave Background.
         /// </summary>
@@ -57,6 +63,11 @@ namespace Content.Shared.Atmos
         /// </summary>
         public const float MolesCellStandard = (OneAtmosphere * CellVolume / (T20C * R));
 
+        /// <summary>
+        ///     Moles in a 2.5 m^3 cell at GasMinerDefaultMaxExternalPressure kPa and 20ºC
+        /// </summary>
+        public const float MolesCellGasMiner = (GasMinerDefaultMaxExternalPressure * CellVolume / (T20C * R));
+
         /// <summary>
         ///     Compared against for superconduction.
         /// </summary>