4.2. Input Syntax

Note

Page under construction. The input syntax can be found at: https://nextnano-docu.northeurope.cloudapp.azure.com/dokuwiki/doku.php?id=qcl:input_file

Two formats are supported by the nextnano.NEGF software. * the .xml format (supported in all versions) * the .negf format (similar style as nextnano++ .in format, available only in the new C++ version)

The new format with 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_DatabaseCpp.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

    • The section Variables has been deprecated. Please add manually your variables in the nextnano++ format, i.e., define the variables at the beginning of your input file as $variable = value (See Input Syntax).

    • 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 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 mandatory sections are the following: * Materials (definition of materials used in the structure) * SimulationParameter (simulation parameters)