diff --git a/montepy/__init__.py b/montepy/__init__.py
index 3d67eaaf..560e46b2 100644
--- a/montepy/__init__.py
+++ b/montepy/__init__.py
@@ -28,7 +28,7 @@
 from .input_parser.input_reader import read_input
 
 # top level
-from montepy.particle import Particle
+from montepy.particle import Particle, LibraryType
 from montepy.universe import Universe
 from montepy.cell import Cell
 from montepy.mcnp_problem import MCNP_Problem
diff --git a/montepy/particle.py b/montepy/particle.py
index 21359266..864fb40a 100644
--- a/montepy/particle.py
+++ b/montepy/particle.py
@@ -1,9 +1,9 @@
 # Copyright 2024, Battelle Energy Alliance, LLC All Rights Reserved.
-from enum import Enum, unique
+from enum import StrEnum, unique
 
 
 @unique
-class Particle(Enum):
+class Particle(StrEnum):
     """
     Supported MCNP supported particles.
 
@@ -53,3 +53,33 @@ def __lt__(self, other):
 
     def __str__(self):
         return self.name.lower()
+
+
+@unique
+class LibraryType(StrEnum):
+    """
+
+    Taken from section of 5.6.1 of LA-UR-22-30006
+    """
+
+    def __new__(cls, value, particle=None):
+        obj = str.__new__(cls)
+        obj._value_ = value
+        obj._particle_ = particle
+        return obj
+
+    NEUTRON = ("NLIB", Particle.NEUTRON)
+    PHOTO_ATOMIC = ("PLIB", None)
+    PHOTO_NUCLEAR = ("PNLIB", None)
+    ELECTRON = ("ELIB", Particle.ELECTRON)
+    PROTON = ("HLIB", Particle.PROTON)
+    ALPHA_PARTICLE = ("ALIB", Particle.ALPHA_PARTICLE)
+    HELION = ("SLIB", Particle.HELION)
+    TRITON = ("TLIB", Particle.TRITON)
+    DEUTERON = ("DLIB", Particle.DEUTERON)
+
+    def __str__(self):
+        return self.name.lower()
+
+    def __lt__(self, other):
+        return self.value < other.value
diff --git a/montepy/surfaces/surface_type.py b/montepy/surfaces/surface_type.py
index bd440c53..c74c1fba 100644
--- a/montepy/surfaces/surface_type.py
+++ b/montepy/surfaces/surface_type.py
@@ -1,9 +1,9 @@
 # Copyright 2024, Battelle Energy Alliance, LLC All Rights Reserved.
-from enum import unique, Enum
+from enum import unique, StrEnum
 
 
-# @unique
-class SurfaceType(str, Enum):
+@unique
+class SurfaceType(StrEnum):
     """
     An enumeration of the surface types allowed.