diff --git a/pureMaterials/createPurematlib.py b/pureMaterials/createPurematlib.py
old mode 100755
new mode 100644
index 0630670..0c8e4a5
--- a/pureMaterials/createPurematlib.py
+++ b/pureMaterials/createPurematlib.py
@@ -6,73 +6,154 @@
 # -can be used for mixing homogenized regions
 # -generally impurities at <~1e-3 wt. percent (10 wppm) are removed from materials
 #   (except SS-316 steels may contain boron impurity)
-# 
+#
 #
 import os
+from typing import Dict, Union, Optional
 from pyne import material
 from pyne.material import Material, MultiMaterial
 from pyne.material_library import MaterialLibrary
+from pyne import nucname
 #
 #
 
-def make_mat(nucvec, density, citation, molecular_mass = None):
-    mat = Material(nucvec, density = density, metadata = {'citation' : citation})
+
+def enrich(
+    nucvec: Dict[int, float], old_key: int, new_values: Dict[int, float]
+) -> Dict[int, float]:
+    """Update nuclear vector by replacing an old key with new key-value pairs."""
+
+    if old_key in nucvec:
+        fract = nucvec.pop(old_key)
+        for key, value in new_values.items():
+            nucvec[key] = value * fract
+    else:
+        found_key = None
+        for key in list(nucvec.keys()):
+            if nucname.id(old_key) == nucname.id(key):
+                found_key = key
+                break
+
+        if found_key is not None:
+            fract = nucvec.pop(found_key)
+            for new_key, value in new_values.items():
+                nucvec[new_key] = value * fract  # check if percent works also
+
+    return nucvec
+
+
+def make_mat(
+    nucvec: Dict[int, float],
+    density: float,
+    citation: str,
+    molecular_mass: Optional[float] = None,
+    mass_enrichment: Optional[Dict[int, Dict[int, float]]] = None,
+) -> Material:
+    """Create a Material object from nuclear vector data."""
+    if mass_enrichment:
+        for element, enrichment_vector in mass_enrichment.items():
+            enriched_mat = Material(enrichment_vector)
+            nucvec = enrich(nucvec, element, enriched_mat.comp)
+    mat = Material(nucvec, density=density, metadata={"citation": citation})
     if molecular_mass:
         mat.molecular_mass = molecular_mass
     return mat.expand_elements()
 
-def make_mat_from_atom(atom_frac, density, citation):
+
+def make_mat_from_atom(
+    atom_frac: Dict[Union[int, str], float],
+    density: float,
+    citation: str,
+    mass_enrichment: Optional[Dict[int, Dict[int, float]]] = None,
+) -> Material:
+    """Create a Material object from atom fraction data."""
+    if mass_enrichment:
+        for element, enrichment_vector in mass_enrichment.items():
+            enriched_mat = Material(enrichment_vector)
+            atom_frac = enrich(atom_frac, element, enriched_mat.to_atom_frac())
+
     mat = Material()
     mat.from_atom_frac(atom_frac)
     mat.density = density
-    mat.metadata['citation'] = citation
+    mat.metadata["citation"] = citation
     return mat.expand_elements()
 
 mat_data = {}
 
 # fullreference: KluehJNM_2000 R.L. Klueh et al. jnm 2000 DOI:10.1016/S0022-3115(00)00060-X
-mat_data['MF82H'] = {
-    'nucvec' : {60000000: 0.1, 230000000: 0.2, 240000000: 7.5, 260000000: 90.18, 730000000: 0.02, 740000000: 2.0},
-    'density' : 7.89,
-    'citation' : 'KluehJNM_2000'
-    }
+mat_data["MF82H"] = {
+    "nucvec": {
+        60000000: 0.1,
+        230000000: 0.2,
+        240000000: 7.5,
+        260000000: 90.18,
+        730000000: 0.02,
+        740000000: 2.0,
+    },
+    "density": 7.89,
+    "citation": "KluehJNM_2000",
+}
 
 # fullreference: ChenNucEngTech_2013 Y. Chen Nuclear and Engineering Technology, vol. 45, 2013. https://doi.org/10.5516/NET.07.2013.706
 # fullreference: SmithBCSSANLvol2_1984, D.L. Smith et al., "Blanket Comparison and Selection Study Final Report", ANL/FPP-84-1, volume 2, Chapter 6, 1984. (HT-9 density pdf page 32 and 49)
-mat_data['HT9'] = {
-    'nucvec' : {60000000: 0.2, 230000000: 0.25, 240000000: 12.0, 260000000: 85.55, 280000000: 0.5, 420000000: 1.0, 740000000: 0.5},
-    'density' : 7.8, # density BCSSvol2 pdf page 32 and page 49
-    'citation' : 'KluehJNM_2000 and SmithBCSSANLvol2_1984'
-    }
+mat_data["HT9"] = {
+    "nucvec": {
+        60000000: 0.2,
+        230000000: 0.25,
+        240000000: 12.0,
+        260000000: 85.55,
+        280000000: 0.5,
+        420000000: 1.0,
+        740000000: 0.5,
+    },
+    "density": 7.8,  # density BCSSvol2 pdf page 32 and page 49
+    "citation": "KluehJNM_2000 and SmithBCSSANLvol2_1984",
+}
 
 # fullreference: MergiaJNM_2008 K. Mergia, N. Boukos jnm 2008 https://doi.org/10.1016/j.jnucmat.2007.03.267
 # wt percent  0.11C, 8.9Cr, 0.42Mn, 0.19V, 1.10W, 0.14Ta, balance Fe
-mat_data['EUROFER97'] = {
-    'nucvec' : {60000000: 0.11, 230000000: 0.19, 240000000: 8.9, 250000000: 0.42, 260000000: 89.14, 730000000: 0.14, 740000000: 1.10},
-    'density' : 7.75,
-    'citation' : 'MergiaJNM_2008'
-    }
+mat_data["EUROFER97"] = {
+    "nucvec": {
+        60000000: 0.11,
+        230000000: 0.19,
+        240000000: 8.9,
+        250000000: 0.42,
+        260000000: 89.14,
+        730000000: 0.14,
+        740000000: 1.10,
+    },
+    "density": 7.75,
+    "citation": "MergiaJNM_2008",
+}
 
 # reference: KluehJNM_2000 MF82H with 3 wt. percent B replacing some Fe
-mat_data['BMF82H'] = {
-    'nucvec' : {50000000: 3.0, 60000000: 0.1, 230000000: 0.2, 240000000: 7.5, 260000000: 87.18, 730000000: 0.02, 740000000: 2.0},
-    'density' : 7.89,
-    'citation' : 'KluehJNM_2000'
-    }
+mat_data["BMF82H"] = {
+    "nucvec": {
+        50000000: 3.0,
+        60000000: 0.1,
+        230000000: 0.2,
+        240000000: 7.5,
+        260000000: 87.18,
+        730000000: 0.02,
+        740000000: 2.0,
+    },
+    "density": 7.89,
+    "citation": "KluehJNM_2000",
+}
 
 # fullreference: pnnl-15870rev1 R.J. McConn, et al. "Compendium of Material Composition Data for Radiation Transport Modeling", PNNL-15870 Rev. 1, 2011.
-mat_data['Water'] = {
-    'nucvec' : {10000000: 11.1894, 80000000: 88.8106},
-    'density' : 1.0,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Water"] = {
+    "nucvec": {10000000: 11.1894, 80000000: 88.8106},
+    "density": 1.0,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['SiC'] = {
-    'nucvec' : {60000000  : 29.9547, 140000000: 70.0453},
-    'density' : 3.21,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["SiC"] = {
+    "nucvec": {60000000: 29.9547, 140000000: 70.0453},
+    "density": 3.21,
+    "citation": "pnnl-15870rev1",
+}
 
 # note SS-316L(N)-IG and EUROFER composition (but not density) in
 # reference: GilbertNucFus_2017
@@ -84,221 +165,319 @@ def make_mat_from_atom(atom_frac, density, citation):
 
 # reference: GilbertHandbookITERCCFE_2016
 # contains 300 wppm B which is important to assess typical He production level
-mat_data['SS316LN'] = {
-    'nucvec' : {50000000:0.030, 60000000:0.030, 70000000:0.160, 140000000:1.0, 150000000:0.030, 160000000:0.020, 240000000:17.250, 250000000:2.00 , 260000000:64.830, 270000000:0.100, 280000000:12.00, 410000000:0.050, 420000000:2.5},
-    'density' : 7.93,
-    'citation' : 'GilbertHandbookITERCCFE_2016'
-    }
+mat_data["SS316LN"] = {
+    "nucvec": {
+        50000000: 0.030,
+        60000000: 0.030,
+        70000000: 0.160,
+        140000000: 1.0,
+        150000000: 0.030,
+        160000000: 0.020,
+        240000000: 17.250,
+        250000000: 2.00,
+        260000000: 64.830,
+        270000000: 0.100,
+        280000000: 12.00,
+        410000000: 0.050,
+        420000000: 2.5,
+    },
+    "density": 7.93,
+    "citation": "GilbertHandbookITERCCFE_2016",
+}
 
 # reference: GilbertHandbookITERCCFE_2016 10 wppm B which is important to assess typical He production level
-mat_data['SS316LNIG'] = {
-    'nucvec' : {50000000:0.001, 60000000:0.03, 70000000:0.070, 140000000:0.50, 150000000:0.025, 160000000:0.010, 220000000:0.10, 240000000:17.50, 250000000:1.80, 260000000:64.844, 270000000:0.05, 280000000:12.25, 290000000:0.30, 410000000:0.010, 420000000:2.5, 730000000:0.01},
-    'density' : 7.93,
-    'citation' : 'GilbertHandbookITERCCFE_2016'
-    }
+mat_data["SS316LNIG"] = {
+    "nucvec": {
+        50000000: 0.001,
+        60000000: 0.03,
+        70000000: 0.070,
+        140000000: 0.50,
+        150000000: 0.025,
+        160000000: 0.010,
+        220000000: 0.10,
+        240000000: 17.50,
+        250000000: 1.80,
+        260000000: 64.844,
+        270000000: 0.05,
+        280000000: 12.25,
+        290000000: 0.30,
+        410000000: 0.010,
+        420000000: 2.5,
+        730000000: 0.01,
+    },
+    "density": 7.93,
+    "citation": "GilbertHandbookITERCCFE_2016",
+}
 
 # reference: pnnl-15870rev1
 # added 10 wppm B which is important to assess typical He production level
-mat_data['SS316L'] = {
-    'nucvec' : {50000000:0.001, 60000000:0.03, 140000000:1.0, 150000000:0.045, 160000000:0.03, 240000000:17, 250000000:2, 260000000:65.394, 280000000:12, 420000000:2.5},
-    'density' : 8.00,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["SS316L"] = {
+    "nucvec": {
+        50000000: 0.001,
+        60000000: 0.03,
+        140000000: 1.0,
+        150000000: 0.045,
+        160000000: 0.03,
+        240000000: 17,
+        250000000: 2,
+        260000000: 65.394,
+        280000000: 12,
+        420000000: 2.5,
+    },
+    "density": 8.00,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: FESS-FNSF very similar to GFFpolyimide from ARIES
-mat_data['Eins'] = {
-    'nucvec' : {10000000:1.96, 60000000:24.12, 70000000:1.46, 80000000:40.19, 120000000:3.92, 130000000: 8.6, 140000000:19.75},
-    'density' : 1.8,
-    'citation' : 'FESS-FNSF and ARIES GFFpolyimide'
-    }
+mat_data["Eins"] = {
+    "nucvec": {
+        10000000: 1.96,
+        60000000: 24.12,
+        70000000: 1.46,
+        80000000: 40.19,
+        120000000: 3.92,
+        130000000: 8.6,
+        140000000: 19.75,
+    },
+    "density": 1.8,
+    "citation": "FESS-FNSF and ARIES GFFpolyimide",
+}
 
 # fullreference: BohmFusSciTec_2019 https://doi.org/10.1080/15361055.2019.1600930
 # fullreference: MartelliFusEngDes_2019 https://doi.org/10.1016/j.fusengdes.2018.11.028
-mat_data['Pb157Li90'] = {
-    'nucvec' : {30060000: 0.4905, 30070000: 0.0545,820000000: 99.455},
-    'density' : 9.32, # not sure of Temperature
-    'molecular_mass': 175.6273,
-    'citation' : 'BohmFusSciTec_2019'
-    }
+mat_data["Pb157Li90"] = {
+    "nucvec": {30060000: 0.4905, 30070000: 0.0545, 820000000: 99.455},
+    "density": 9.32,  # not sure of Temperature
+    "molecular_mass": 175.6273,
+    "citation": "BohmFusSciTec_2019",
+}
 
 
 # fullreference: ElGuebalyARIESCSFTI_2006 L. El-Guebaly, "Final Radial Build and Composition for LiPb/FS/He System", Sep. 2006. https://fti.neep.wisc.edu/fti.neep.wisc.edu/aries/BUILD-CS/build092606.pdf
 # fullreference: HeizenroederComments2005 P. Heizenroeder and R. Reed "Comments on Selection of U.S. ITER CS Coil Jacket Material", Sep. 12, 2005
-mat_data['JK2LBSteel'] = {
-    'nucvec' : {50000000:0.002, 60000000:0.02, 70000000:0.2, 140000000:0.3, 150000000:0.004, 160000000:0.004, 240000000:13, 250000000:21, 260000000:55.47, 280000000:9, 420000000:1},
-    'density' : 8.0,
-    'citation' : 'ElGuebalyARIESCSFTI_2006'
-    }
+mat_data["JK2LBSteel"] = {
+    "nucvec": {
+        50000000: 0.002,
+        60000000: 0.02,
+        70000000: 0.2,
+        140000000: 0.3,
+        150000000: 0.004,
+        160000000: 0.004,
+        240000000: 13,
+        250000000: 21,
+        260000000: 55.47,
+        280000000: 9,
+        420000000: 1,
+    },
+    "density": 8.0,
+    "citation": "ElGuebalyARIESCSFTI_2006",
+}
 
 # reference: FESS-FNSF and ???
-mat_data['TernaryNb3Sn'] = {
-    'nucvec' : {410000000:68.95, 500000000:30, 220000000:1.05},
-    'density' : 8.9,
-    'citation' : 'FESS-FNSF and ???'
-    }
- 
+mat_data["TernaryNb3Sn"] = {
+    "nucvec": {410000000: 68.95, 500000000: 30, 220000000: 1.05},
+    "density": 8.9,
+    "citation": "FESS-FNSF and ???",
+}
+
 # reference: ITER and CRC Handbook of Chemistry and Physics density at 4 K
 # fullreference: CRChandbook64 64th CRC Handbook of Chemistry and Physics page B-117, density at 4 K
-mat_data['LHe'] = {
-    'nucvec' : {20000000: 100},
-    'density' : 0.149,
-    'citation' : 'CRChandbook64B117'
-    }
+mat_data["LHe"] = {
+    "nucvec": {20000000: 100},
+    "density": 0.149,
+    "citation": "CRChandbook64B117",
+}
 
 # fullreference: JawadORNL_2005 M. Jawad et al. , "Development of a New Class of Fe-3Cr-W(V) Ferritic Steels for Industrial Process Applications", ORNL/TM-2005/82, 2005. https://doi.org/10.2172/838517
-mat_data['Cr3FS'] = {
-    'nucvec' : {60000:0.1, 140000:0.14, 230000:0.25, 240000:3.0, 250000:0.5, 260000:93.01, 740000:3.0},
-    'density' : 7.89,
-    'citation' : 'JawadORNL_2005 and ???'
-    }
+mat_data["Cr3FS"] = {
+    "nucvec": {
+        60000: 0.1,
+        140000: 0.14,
+        230000: 0.25,
+        240000: 3.0,
+        250000: 0.5,
+        260000: 93.01,
+        740000: 3.0,
+    },
+    "density": 7.89,
+    "citation": "JawadORNL_2005 and ???",
+}
 
 # ODS LiPb-corrosion-resistant steel with Present impurities removed
 # fullreference: PintDOE_ER_0313_57_2014 B. Pint et al., DEVELOPMENT OF ODS FeCrAl FOR FUSION REACTOR APPLICATIONS, Fusion Reactor Materials Program Semi-annual Report, Dec. 2014, DOE/ER- 0313/57  Section 2.1, https://fmp.ornl.gov/semiannual-progress-reports/fusion-materials-semiannual-progress-report-57.pdf
 # reference: KluehJNM_2000 (for some impurities)
 # Density = 7.799 g/cm3, as determined for 14YWT alloy, per David Hoelzer
 #
-mat_data['ODS125Y'] = {
-    'nucvec' : {60000000: 0.0380, 70000000:0.0455, 80000000:0.8420, 130000000:4.8, 140000000:0.02, 160000000:0.0020, 220000000:0.01, 240000000:11.4, 260000000:82.6025, 390000000:0.19, 740000000:0.05},
-    'density' : 7.799,
-    'citation' : 'PintDOE_ER_0313_57_2014 and KluehJNM_2000 '
-    }
+mat_data["ODS125Y"] = {
+    "nucvec": {
+        60000000: 0.0380,
+        70000000: 0.0455,
+        80000000: 0.8420,
+        130000000: 4.8,
+        140000000: 0.02,
+        160000000: 0.0020,
+        220000000: 0.01,
+        240000000: 11.4,
+        260000000: 82.6025,
+        390000000: 0.19,
+        740000000: 0.05,
+    },
+    "density": 7.799,
+    "citation": "PintDOE_ER_0313_57_2014 and KluehJNM_2000 ",
+}
 
 # reference: pnnl-15870rev1 at T=20C
-mat_data['D2O'] = {
-    'nucvec' : {10020000:20.1133, 80000000:79.8867},
-    'density' : 1.10534,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["D2O"] = {
+    "nucvec": {10020000: 20.1133, 80000000: 79.8867},
+    "density": 1.10534,
+    "citation": "pnnl-15870rev1",
+}
 
 # fullreference: WidodoJoPCS_2018 Journal of Physics Conference Series doi:10.1088/1742-6596/962/1/012039 and KTA Standards 1986
 # also reference: pnnl-15870rev1
-mat_data['HeNIST'] = {
-    'nucvec' : {20000000: 100},
-    'density' : 0.00016647, # at 20 C (293.15 K), 1 atm (1.01325 bar)
-    'citation' : 'WidodoJoPCS_2018 and pnnl-15870rev1'
-    }
+mat_data["HeNIST"] = {
+    "nucvec": {20000000: 100},
+    "density": 0.00016647,  # at 20 C (293.15 K), 1 atm (1.01325 bar)
+    "citation": "WidodoJoPCS_2018 and pnnl-15870rev1",
+}
 
 # high pressure He gas ref.
 # reference: WidodoJoPCS_2018 doi:10.1088/1742-6596/962/1/012039 and KTA Standards 1986
-mat_data['HeT410P1'] = {
-    'nucvec' : {20000000: 100},
-    'density' : 0.00007048, # at 410 C, 1 bar
-    'citation' : 'WidodoJoPCS_2018'
-    }
-
-mat_data['HeT410P80'] = {
-    'nucvec' : {20000000: 100},
-    'density' : 0.00571698, # at 410 C, 80 bar
-    'citation' : 'WidodoJoPCS_2018'
-    }
+mat_data["HeT410P1"] = {
+    "nucvec": {20000000: 100},
+    "density": 0.00007048,  # at 410 C, 1 bar
+    "citation": "WidodoJoPCS_2018",
+}
+
+mat_data["HeT410P80"] = {
+    "nucvec": {20000000: 100},
+    "density": 0.00571698,  # at 410 C, 80 bar
+    "citation": "WidodoJoPCS_2018",
+}
 
 # air (Dry, Near Sea Level)
 # reference: pnnl-15870rev1
-mat_data['AirSTP'] = {
-    'nucvec' : {60000000  : 0.0124, 70000000  : 75.5268, 80000000  : 23.1781, 180000000: 1.2827},
-    'density' : 0.001205,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["AirSTP"] = {
+    "nucvec": {
+        60000000: 0.0124,
+        70000000: 75.5268,
+        80000000: 23.1781,
+        180000000: 1.2827,
+    },
+    "density": 0.001205,
+    "citation": "pnnl-15870rev1",
+}
 
 # concrete (Ordinary NBS 04)
 # reference: pnnl-15870rev1
-mat_data['Concrete'] = {
-    'nucvec' : {10000000  : 0.5558, 80000000  : 49.8076, 110000000: 1.7101, 120000000: 0.2565, 130000000: 4.5746, 140000000: 31.5092, 160000000: 0.1283, 190000000: 1.9239, 200000000: 8.2941, 260000000: 1.2398},
-    'density' : 2.35,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Concrete"] = {
+    "nucvec": {
+        10000000: 0.5558,
+        80000000: 49.8076,
+        110000000: 1.7101,
+        120000000: 0.2565,
+        130000000: 4.5746,
+        140000000: 31.5092,
+        160000000: 0.1283,
+        190000000: 1.9239,
+        200000000: 8.2941,
+        260000000: 1.2398,
+    },
+    "density": 2.35,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['W'] = {
-    'nucvec' : {740000000: 100.0},
-    'density' : 19.30,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["W"] = {
+    "nucvec": {740000000: 100.0},
+    "density": 19.30,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['Fe'] = {
-    'nucvec' : {260000000: 100.0},
-    'density' : 7.874,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Fe"] = {
+    "nucvec": {260000000: 100.0},
+    "density": 7.874,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['Na'] = {
-    'nucvec' : {110000000: 100.0},
-    'density' : 0.971,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Na"] = {
+    "nucvec": {110000000: 100.0},
+    "density": 0.971,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1 reactor graphite without boron impurity
-mat_data['C'] = {
-    'nucvec' : {60000000:1.0},
-    'density' : 1.7,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["C"] = {
+    "nucvec": {60000000: 1.0},
+    "density": 1.7,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['Si'] = {
-    'nucvec' : {140000000:1.0},
-    'density' : 2.33,
-    'citation' : 'pnnl-15870rev1'
-    }
-    
+mat_data["Si"] = {
+    "nucvec": {140000000: 1.0},
+    "density": 2.33,
+    "citation": "pnnl-15870rev1",
+}
+
 # reference: pnnl-15870rev1
-mat_data['Cu'] = {
-    'nucvec' : {290000000:1.0},
-    'density' : 8.96,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Cu"] = {
+    "nucvec": {290000000: 1.0},
+    "density": 8.96,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference:  pnnl-15870rev1
-mat_data['Sn'] = {
-    'nucvec' : {500000000:1.0},
-    'density' : 7.31,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Sn"] = {
+    "nucvec": {500000000: 1.0},
+    "density": 7.31,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['Ta'] = {
-    'nucvec' : {730000000:1.0},
-    'density' : 16.654, 
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Ta"] = {
+    "nucvec": {730000000: 1.0},
+    "density": 16.654,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['Pb'] = {
-    'nucvec' : {820000000: 100.0},
-    'density' : 11.35,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Pb"] = {
+    "nucvec": {820000000: 100.0},
+    "density": 11.35,
+    "citation": "pnnl-15870rev1",
+}
 
 # fullreference: HernandezFusEngDes_2018 F.A. Hernandez, P. Pereslavtsev, Fusion Engineering and Design vol. 137, 2018 https://doi.org/10.1016/j.fusengdes.2018.09.014
-mat_data['Be'] = {
-    'nucvec' : {40000000:1.0},
-    'density' : 1.85,
-    'citation' : 'HernandezFusEngDes_2018'
-    }
+mat_data["Be"] = {
+    "nucvec": {40000000: 1.0},
+    "density": 1.85,
+    "citation": "HernandezFusEngDes_2018",
+}
 
 # reference:  HernandezFusEngDes_2018
 # F.A. Hernandez, P. Pereslavtsev, Fusion Engineering and Design vol. 137, 2018
 # https://doi.org/10.1016/j.fusengdes.2018.09.014
-mat_data['Be12Ti'] = {
-    'atom_frac' : {40000000:12,220000000:1},
-    'density' : 2.28,
-    'citation' : 'HernandezFusEngDes_2018'
-    }
+mat_data["Be12Ti"] = {
+    "atom_frac": {40000000: 12, 220000000: 1},
+    "density": 2.28,
+    "citation": "HernandezFusEngDes_2018",
+}
 
 # reference:  HernandezFusEngDes_2018
 # F.A. Hernandez, P. Pereslavtsev, Fusion Engineering and Design vol. 137, 2018
 # https://doi.org/10.1016/j.fusengdes.2018.09.014
-mat_data['Be12V'] = {
-    'atom_frac' : {40000000:12,230000000:1},
-    'density' : 2.39,
-    'citation' : 'HernandezFusEngDes_2018'
-    }
+mat_data["Be12V"] = {
+    "atom_frac": {40000000: 12, 230000000: 1},
+    "density": 2.39,
+    "citation": "HernandezFusEngDes_2018",
+}
 
-li6enrichment = 0.60 # weight fraction enrichment of Li-6 desired
-li6enrichStr = f'Li{li6enrichment * 100}'
-liXweightfraction = Material({'Li6': li6enrichment, 'Li7': (1.0-li6enrichment)})
+li6enrichment = 0.60  # weight fraction enrichment of Li-6 desired
+li6enrichStr = f"Li{li6enrichment * 100}"
+liXweightfraction = Material({"Li6": li6enrichment, "Li7": (1.0 - li6enrichment)})
 
 # Li ceramics
 # reference: HernandezFusEngDes_2018 F.A. Hernandez, P. Pereslavtsev, Fusion Engineering and Design vol. 137, 2018 https://doi.org/10.1016/j.fusengdes.2018.09.014
@@ -307,176 +486,202 @@ def make_mat_from_atom(atom_frac, density, citation):
 # ceramic breeders Li4SiO4 and Li2TiO3 at 60 wt. percent Li-6 EU-DEMO
 # note manufacturing may result in lower density of 80-90% of theoretical
 
-mat_data['Li4SiO4nat'] = {
-    'atom_frac' : {30000000:4, 80000000:4, 140000000:1},
-    'density' : 2.40,
-    'citation' : 'HernandezFusEngDes_2018'
-    }
-
-mat_data['Li2TiO3nat'] = {
-    'atom_frac' : {30000000:2, 80000000:3, 220000000:1},
-    'density' : 3.43,
-    'citation' : 'HernandezFusEngDes_2018'
-    }
-
-mat_data['Li4SiO4' + li6enrichStr] = {
-    'atom_frac' : {liXweightfraction:4, 80000000:4, 140000000:1},
-    'density' : 2.40,
-    'citation' : 'HernandezFusEngDes_2018'
-    }
-
-mat_data['Li2TiO3' + li6enrichStr] = {
-    'atom_frac' : {liXweightfraction:2, 80000000:3, 220000000:1},
-    'density' : 3.42,
-    'citation' : 'HernandezFusEngDes_2018'
-    }
+mat_data["Li4SiO4nat"] = {
+    "atom_frac": {30000000: 4, 80000000: 4, 140000000: 1},
+    "density": 2.40,
+    "citation": "HernandezFusEngDes_2018",
+}
+
+mat_data["Li2TiO3nat"] = {
+    "atom_frac": {30000000: 2, 80000000: 3, 220000000: 1},
+    "density": 3.43,
+    "citation": "HernandezFusEngDes_2018",
+}
+
+mat_data["Li4SiO4" + li6enrichStr] = {
+    "atom_frac": {liXweightfraction: 4, 80000000: 4, 140000000: 1},
+    "density": 2.40,
+    "citation": "HernandezFusEngDes_2018",
+}
+
+mat_data["Li2TiO3" + li6enrichStr] = {
+    "atom_frac": {liXweightfraction: 2, 80000000: 3, 220000000: 1},
+    "density": 3.42,
+    "citation": "HernandezFusEngDes_2018",
+}
 
 # fullreference: SohalINLEXT-10-18297_2013 M. Sohal et al., "Engineering Database of Liquid Salt Thermophysical and Thermochemical Properties", INL/EXT-10-18297, June 2013. https://inldigitallibrary.inl.gov/sites/STI/STI/5698704.pdf
-mat_data['FlibeNat'] = {
-    'atom_frac' : {30000000:2,40000000:1,90000000:4},
-    'density' : 1.94,
-    'citation' : 'SohalINLEXT-10-18297_2013'
-    }
+mat_data["FlibeNat"] = {
+    "atom_frac": {30000000: 2, 40000000: 1, 90000000: 4},
+    "density": 1.94,
+    "citation": "SohalINLEXT-10-18297_2013",
+}
 
 # reference: SohalINLEXT-10-18297_2013 M. Sohal et al., "Engineering Database of Liquid Salt Thermophysical and Thermochemical Properties", INL/EXT-10-18297, June 2013. https://inldigitallibrary.inl.gov/sites/STI/STI/5698704.pdf
-mat_data['Flibe' + li6enrichStr] = {
-    'atom_frac' : {liXweightfraction:2,40000000:1,90000000:4},
-    'density' : 1.94,
-    'citation' : 'SohalINLEXT-10-18297_2013'
-    }
+mat_data["Flibe" + li6enrichStr] = {
+    "atom_frac": {liXweightfraction: 2, 40000000: 1, 90000000: 4},
+    "density": 1.94,
+    "citation": "SohalINLEXT-10-18297_2013",
+}
 
 # reference:  pnnl-15870rev1 at STP
-mat_data['LiNat'] = {
-    'nucvec' : {30000000:1.0},
-    'density' : 0.534, # at STP
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["LiNat"] = {
+    "nucvec": {30000000: 1.0},
+    "density": 0.534,  # at STP
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: BohmFusSciTec_2019 rho=0.485 g/cm3 at T=500 C
-mat_data['LiNatT500'] = {
-    'nucvec' : {30000000:1.0},
-    'density' : 0.485, # at T=500 C
-    'citation' : 'BohmFusSciTec_2019'
-    }
+mat_data["LiNatT500"] = {
+    "nucvec": {30000000: 1.0},
+    "density": 0.485,  # at T=500 C
+    "citation": "BohmFusSciTec_2019",
+}
 
 # reference:  pnnl-15870rev1
 mat_data[li6enrichStr] = {
-    'atom_frac' : {liXweightfraction:1},
-    'density' : 0.534, # at STP
-    'citation' : 'pnnl-15870rev1'
-    }
+    "atom_frac": {liXweightfraction: 1},
+    "density": 0.534,  # at STP
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: BohmFusSciTec_2019 rho=0.485 g/cm3 at T=500 C
-mat_data[li6enrichStr + 'T500'] = {
-    'atom_frac' : {liXweightfraction:1},
-    'density' : 0.485, # at T=500 C
-    'citation' : 'BohmFusSciTec_2019'
-    }
+mat_data[li6enrichStr + "T500"] = {
+    "atom_frac": {liXweightfraction: 1},
+    "density": 0.485,  # at T=500 C
+    "citation": "BohmFusSciTec_2019",
+}
 
 # reference: pnnl-15870rev1
-mat_data['Mo'] = {
-    'nucvec' : {420000000: 100.0},
-    'density' : 10.22,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Mo"] = {
+    "nucvec": {420000000: 100.0},
+    "density": 10.22,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['Aluminum6061'] = {
-    'nucvec' : {120000000:1.0, 130000000:97.2, 140000000:0.6, 220000000:0.088, 240000000:0.195, 250000000:0.088, 260000000:0.4090, 290000000:0.275, 300000000:0.146},
-    'density' : 2.70,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["Aluminum6061"] = {
+    "nucvec": {
+        120000000: 1.0,
+        130000000: 97.2,
+        140000000: 0.6,
+        220000000: 0.088,
+        240000000: 0.195,
+        250000000: 0.088,
+        260000000: 0.4090,
+        290000000: 0.275,
+        300000000: 0.146,
+    },
+    "density": 2.70,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['OilTexasCrude'] = {
-    'nucvec' : {10000000:12.3246, 60000000:85.2204, 70000000:0.7014, 160000000:1.7535},
-    'density' : 0.875,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["OilTexasCrude"] = {
+    "nucvec": {
+        10000000: 12.3246,
+        60000000: 85.2204,
+        70000000: 0.7014,
+        160000000: 1.7535,
+    },
+    "density": 0.875,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['EthyleneGlycol'] = {
-    'atom_frac' : {10000000:6, 60000000:2, 80000000:2},
-    'density' : 1.114,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["EthyleneGlycol"] = {
+    "atom_frac": {10000000: 6, 60000000: 2, 80000000: 2},
+    "density": 1.114,
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: pnnl-15870rev1
-mat_data['AluminumOxide'] = {
-    'atom_frac' : {80000000:3, 130000000:2},
-    'density' : 3.97,
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["AluminumOxide"] = {
+    "atom_frac": {80000000: 3, 130000000: 2},
+    "density": 3.97,
+    "citation": "pnnl-15870rev1",
+}
 
 # fullreference: GrossbeckJNM_1998 M.L. Grossbeck et al.,"Analysis of V-Cr-Ti alloys in terms of activation of impurities", Journal of Nuclear Materials, vol. 258-263, page 1778-1783 1998. https://doi.org/10.1016/S0022-3115(98)00228-1
-# fullreference: ARIES_PropertiesArchive http://qedfusion.org/LIB/PROPS/ 
+# fullreference: ARIES_PropertiesArchive http://qedfusion.org/LIB/PROPS/
 # fullreference: MetalsHandbook_1979 Metals Handbook, Ninth Edition, Vol. 2: "Properties and SelectionNonferrous Alloys and Pure Metals," ASM, Metals Park OH (1979)
-mat_data['V4Cr4Ti'] = {
-    'nucvec' : {220000000: 4.0,230000000: 92.0, 240000000: 4.0},
-    'density' : 6.05, # room temperature
-    'citation' : 'GrossbeckJNM_1998 and density ARIES_PropertiesArchive and MetalsHandbook_1979'
-    }
-
-mat_data['ZrH2'] = {
-    'atom_frac' : {10000000: 2,400000000: 1},
-    'density' : 5.61, #this is at room temperature
-    'citation' : 'pnnl-15870rev1'
-    }
-
-# 
-mat_data['Inconel718'] = {
-    'nucvec' :  { 50000000: 0.0050,
-                  60000000: 0.0730,
-                 130000000: 0.5000,
-                 140000000: 0.3180,
-                 150000000: 0.0140,
-                 160000000: 0.0140,
-                 220000000: 0.9000,
-                 240000000: 19.0000,
-                 250000000: 0.3180,
-                 260000000: 17.0000,
-                 280000000: 52.5000,
-                 270000000: 0.9100,
-                 290000000: 0.2730,
-                 410000000: 5.1250,
-                 420000000: 3.0500},
-    'density' : 8.19, # room temperature
-    'citation' : 'pnnl-15870rev1'
-    }
+mat_data["V4Cr4Ti"] = {
+    "nucvec": {220000000: 4.0, 230000000: 92.0, 240000000: 4.0},
+    "density": 6.05,  # room temperature
+    "citation": "GrossbeckJNM_1998 and density ARIES_PropertiesArchive and MetalsHandbook_1979",
+}
+
+mat_data["ZrH2"] = {
+    "atom_frac": {10000000: 2, 400000000: 1},
+    "density": 5.61,  # this is at room temperature
+    "citation": "pnnl-15870rev1",
+}
+
+#
+mat_data["Inconel718"] = {
+    "nucvec": {
+        50000000: 0.0050,
+        60000000: 0.0730,
+        130000000: 0.5000,
+        140000000: 0.3180,
+        150000000: 0.0140,
+        160000000: 0.0140,
+        220000000: 0.9000,
+        240000000: 19.0000,
+        250000000: 0.3180,
+        260000000: 17.0000,
+        280000000: 52.5000,
+        270000000: 0.9100,
+        290000000: 0.2730,
+        410000000: 5.1250,
+        420000000: 3.0500,
+    },
+    "density": 8.19,  # room temperature
+    "citation": "pnnl-15870rev1",
+}
 
 # reference: aries.ucsd.edu/PROPS/ITER/AM01/AM01-1100.html
 # fullreference: CRChandbook64 Bulk density of WC: 64th CRC Handbook of Chemistry and Physics, B-152
-mat_data['WC'] = {
-    'atom_frac' : {60000000:1,740000000:1},
-    'density' : 15.63,
-    'citation' : 'CRChandbook64B152'
-    }
+mat_data["WC"] = {
+    "atom_frac": {60000000: 1, 740000000: 1},
+    "density": 15.63,
+    "citation": "CRChandbook64B152",
+}
+
 
 # --------------------------------------------------------
 def main():
-    # create material library object
+    """Main function to create and write Pure Fusion Materials."""
     mat_lib = MaterialLibrary()
-    print( "\n Creating Pure Fusion Materials...")
-    #
-    # get material definition
+    print("\nCreating Pure Fusion Materials...")
+
     for mat_name, mat_input in mat_data.items():
-        if 'nucvec' in mat_input:
-            mat_lib[mat_name] = make_mat(mat_input['nucvec'], mat_input['density'], mat_input['citation'], 
-                                         mat_input.get('molecular_mass'))
-        if 'atom_frac' in mat_input:
-            mat_lib[mat_name] = make_mat_from_atom(mat_input['atom_frac'], mat_input['density'], mat_input['citation'])
-    
+        if "nucvec" in mat_input:
+            mat_lib[mat_name] = make_mat(
+                mat_input["nucvec"],
+                mat_input["density"],
+                mat_input["citation"],
+                mat_input.get("molecular_mass"),
+                mat_input.get("mass_enrichment"),
+            )
+        elif "atom_frac" in mat_input:
+            mat_lib[mat_name] = make_mat_from_atom(
+                mat_input["atom_frac"],
+                mat_input["density"],
+                mat_input["citation"],
+                mat_input.get("mass_enrichment"),
+            )
     # remove lib
-    try: 
+    try:
         os.remove("PureFusionMaterials_libv1.json")
-    except: 
-        pass  
-        
+    except:
+        pass
+
     # write fnsf1d material library
     mat_lib.write_json("PureFusionMaterials_libv1.json")
 
     print("All done!")
-    
-    
+
+
 if __name__ == "__main__":
     main()