MCNP5 incorrectly assumes that the photon Compton broadening data provided in the MCPLIB03 and MCPLIB04 libraries provides the probability of interacting with a given electron shell as a cumulative probability distribution (CDF). The data are given as a probability density function (PDF) as this was the original way in which the data where provided and this maintains higher precision for the stored data.
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.
MCPLIB63 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