The ENDF70 Library

    Released: 2006-07-22

    ENDF70 is a continuous-energy neutron data library for use with MCNP versions 4C and later (required because of the tabular angular distributions). The library contains data from 390 of the 393 ENDF/B-VII.0 evaluated nuclear data files. The data were processed using the NJOY99.248 code and include, as appropriate, data for:

    • delayed-neutron spectra,
    • unresolved-resonance probability tables,
    • detailed charged-particle production,
    • and using tabular angular distributions.

    The ENDF70 library, due to its 8GB size, is stored in 11 separate files (endf70[a-k]) and contains data for 5 temperatures:

    • .70c 293.6 K
    • .71c 600 K
    • .72c 900 K
    • .73c 1200 K
    • .74c 2500 K

    The ENDF70 library is the first ACE library release based on the ENDF/B-VII library and the first major release since the ENDF66 library. It supersedes the ACTI library (based on ENDF/B-VI, Release 8), ENDF66 library (based on ENDF/B-VI, Release 6), URESA library (based on ENDF/B-VI, Release 4), and ENDF60 library (based on ENDF/B-VI, Release 2). These ENDF/B-VI based libraries have been in production use since 2002. The ENDF/B-VII library represents a major update to the ENDF/B library. It is based on a revised set of international standard cross sections, includes major updates for almost all the actinides, an entirely new set of fission product data, and updates to many of the light isotopes and structural materials.


    1. "ENDF70: A Continuous-Energy MCNP Neutron Data Library Based On ENDF/B-VII.0," Trellue, H.R., Little, R.C., Morgan, C.W., MacFarlane, R.E., Kahler, A.C.S., (2008), LA-UR-08-2000 viewgraphs
    2. "ENDF70: A Continuous-Energy Neutron Data Library Based on ENDF/B-VII.0," Little, R.C., Trellue, H.R., MacFarlane, R.E., Kahler, A.C., Lee, M.B., White, M.C., (2008), LA-UR-08-2909
    3. "Evaluation of Neutron Reactions for ENDF/B-VII: 232−241U and 239Pu," Young, P.G., Chadwick, M.B., MacFarlane, R.E., Talou, P., Kawano, T., Madland, D.G., Wilson, W.B., Wilkerson, C.W., (2007) doi:10.1016/j.nds.2007.11.002
    4. "New ACE-Formatted Neutron and Proton Libraries Based on ENDF/B-VII.0," Trellue, H.R., Little, R.C., Lee, M.B., (2008), LA-UR-08-1999
    5. "The NJOY Temperature Bug in PURR and a List of Affected Materials," Goorley, T., (2014), LA-UR-14-24738
    6. "ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology," Chadwick, M.B., et. al., (2006), UCRL-JRNL-225066
    7. "Methods for Processing ENDF/B-VII with NJOY," Macfarlane, R.E., Kahler, A.C., LA-UR-10-04652


    1. "Benchmarking ENDF/B-VII.0," Marck, S.C., (2006) doi:10.1016/j.nds.2006.11.002


    ENDF70 can be downloaded either as a zip file or as a compressed tarball

    • (sha512 d6638139029129ff804bec4d385a7b6cd776c9a8db206591aa7e2d640952b9c3ddaaea56c7f7d878d591fbc10ae4f8a40b3f1b50a51612bc4b902591efdad6a7)
    • endf70.tgz (sha512 efb3308539f03af374b1c964527f40a49fd09aa4c3c1bd4753a9979974c7d261fef0f076f7fa7b8dc9f7f969519d79b79debcadf108d27d6942c1f24425db973)

    If further information is required contact a member of the Data Team by e-mail at