An extensive software documentation is available here:
www.nextnano.de/nextnano3/index.htm

The keywords and specifiers that are used in the input file are described here:
Input file

The keywords and specifiers that are used in the database are described here:
Database

Tool to create input files
Input file generator (1D)

If you have any questions, please don't hesitate to contact support [at] nextnano.de.

ICODE offers a platform to use nextnano³ via a web browser.

g95 is a free Fortran 95 compiler which compiles nextnano³ on various platforms.
In case performance is important, we recommend commercial compilers.