4.6. Input Syntax

The structure and all simulation parameters are specified in input files which can be edited by the users.

The nextnano.NEGF tool supports two formats:

  • the .xml format - supported in all versions

  • the .negf format - identical grammar as .in format of nextnano++, but with different keywords. Available only in the new C++ version (Release Notes).

The new format with the extension .negf features:

  • Syntax validation before the simulation - the parser checks the syntactical correctness as well as the logic and, if invalid, prints an error message in the log specifying what exactly is wrong in your file.

  • Variables starting with $ sign can be used not only in the input but also database files. The new default database Material_Database.negf contains a switch $NEGF / $MSB / $nnp to use the default parameters of nextnano.NEGF, nextnano.MSB, and nextnano++, respectively. Naturally, the new format will look much familiar if you have experience with nextnano++.

  • The nextnanomat feature Tools > Convert .xml Input File to .negf Input File can convert your xml input files to the new format. On Linux, you can run the executable syntax_converter included in the package. After conversion, please note that

    • Most of the XML comments <!-- --> are not retained in the conversion. If necessary, please recover them manually. Comments start with the letter #.

    • Within the new format, only the new input file keywords are supported. They are replaced automatically by the conversion.

    • IMPORTANT: Do not convert the XML database to the new format! The new database Material_Database.negf is not backward-compatible and contains extra parameters compared to Material_Database.xml.

The grammar of the .negf format is identical to that of nextnano++. Please refer to Input Syntax. The .xml format is explained in our old documentation.

Last update: 28/10/2024