There are four photon transport libraries maintained by X-5 and distributed with MCNP: MCPLIB, MCPLIB02, MCPLIB03 and MCPLIB04.
MCPLIB03  was officially released in 2002 as another extension of the MCPLIB/MCPLIB02 data set. The cross section, form factor and fluorescence data on MCPLIB02 and MCPLIB03 are identical. MCPLIB03 includes the addition of the momentum profile (CDBD) data, derived from the work of Biggs, Mendelsohn & Mann .
The MCPLIB63 and MCPLIB84 data libraries are new versions of the MCPLIB03 and MCPLIB04 data libraries where the probability of interacting with a given shell is stored using as a cumulative distribution function. MCPLIB63 and MCPLIB84 can be called using the library ID's
.84c respectively. The choice of IDs is intended to keep these updates out of the general sequence of releases and indicate their special nature. It is highly recommended
that users of MCNP5 download these updated libraries and replace their existing XSDIR file with a version that includes the MCPLIB63 and MCPLIB84 entries and does not include any reference to the MCPLIB03 and MCPLIB04 versions.
M. C. White, "Photoatomic Data Library MCPLIB03: An Update To MCPLIB02 Containing New Compton Doppler Broadening Data," (2002), LANL internal memorandum X-5:MCW-02-110 and LA-UR-03-0787
F. Biggs, L. B. Mendelsohn, and J. B. Mann, "Hartree-Fock Compton Profiles For The Elements," Atomic Data and Nuclear Data Tables, Volume 16, pp. 201-309 (1975).
"Further Notes on MCPLIB03/04 and New MCPLIB63/84 Compton Broadening Data For All Versions of MCNP5," White, M.C., (2012) LA-UR-12-00018
MCPLIB03 can be downloaded either as a zip file or as a compressed tarball
If further information is required contact a member of the Data Team by e-mail at firstname.lastname@example.org