MCNP (Monte Carlo N-Particle) is a transport code that is used throughout the physics community to model how particles interact as they travel through a system. The code is quite old, and therefore requires tweaking to get it running on newer systems like Mac OS X 10.4.10. There are programs and compilers it needs to use when installing that aren’t included in Mac OS X anymore due to their age, and a few that are on the Mac OS X CD that came with your computer, but aren’t installed by default. The first things we need are:
A FORTRAN-77 compiler and a ‘C’ compiler of the same version.
The ‘fsplit’ program.
The XCode tools.