The NXP® Advanced Diode model is an extension to normal diode models to include a much better description of especially the reverse behavior. The model includes the following physical mechanisms:
Trap-assisted tunnelling (both under forward and reverse bias)
As a result of these extra descriptions also the temperature behavior has also drastically improved, without the need for an extra temperature scaling parameter.
The source code of Advanced Diode model is available here. The file "pmk_device_d500.c" contains the majority of the Advanced Diode model. Please notice that the file is located in the directory source/pmk. If you use the included solver, please make sure that you compile on a system that supports Fortran 77.
The models are included in a dynamically loaded library called SiMKit. SiMKit is related to the following circuit simulators used within NXP:
Pstar, the circuit simulator from NXP
Spectre, the circuit simulator from Cadence
The Advanced Diode level 500 is not available for the ADS simulator.
You can read how to download and install the libraries here.