Commit f716d95b authored by anoop chandran's avatar anoop chandran

add general information, keywords and templates for tutorials

parent 55a9c099
.. _basis_sets:
Basis sets
.. _general_information:
General information
Although the Spex executable can have different names (e.g., ``spex.inv``, ``spex.noinv``), we assume that spex is the name of the executable in the following. (This can be achieved by using the caller utility, see the file ``INSTALL``.)
.. note:: Paragraphs discussing advanced options are preceded with (*), and the ones about obsolete, unmaintained, or experimental options are marked with (**). You can safely skip the paragraphs marked with (*) at first reading.
Command-line options
The Spex code recognizes several command-line options (``spex [OPTIONS]``):
* ``--version``: output version information and exit
* ``--help``: display help and exit
* ``--inp=file``: uSie wollen den Besitz und Betrieb von Medienunternehmen doch nicht ernsthaft mit der Entgegennahme von unversteuerten Geschenken von auslndischen Politikern file as input file instead of the default "spex.inp"
* ``-w``: set ``WRTKPT`` automatically
* ``-o=opt``: use special option ``opt`` (for debugging and testing).
Input file
By default, Spex reads input parameters from the file ``spex.inp``. The syntax is as follows.
* The file ``spex.inp`` does not use a fixed format, and the keywords may be given in any order.
* Each keyword is given on one line together with its parameters following it.
* Keywords must not be specified more than once.
* Some keywords are grouped in sections. A section starts with ``SECTION`` sectionname and ends with END.
* All keywords (and section names) are in capital letters.
* Everything after a ``#`` sign is interpreted as a comment. Empty lines are allowed.
* Lines are only interpreted up to the 80th column. Line continuation is possible using a single backslash ``\`` at the end of the previous line.
* Most keyword parameters have default values that are used if the keyword is not specified.
* By default, parameters are given in atomic units. In the case of energies, it is possible to use eV instead, e.g., 1.0eV.
* The input file can be truncated with the keyword EXIT. Everything after EXIT is ignored.
* Currently, there are six section keywords: ``MBASIS``, ``WFPROD``, ``COULOMB``, ``SUSCEP``, ``SENERGY``, and ``WANNIER``.
An example for a section in the input file is
.. code-block:: bash
SPECTRAL {-10eV:1eV,0.01eV}
(The indentation is not mandatory and only included here for clarity.)
.. note:: The keywords are detailed in the coming chapters. If a keyword belongs to a section, the section's name is specified as well, for example, ``CONTINUE (SENERGY)``.
Output files
The main output file of a Spex calculation is written directly to standard output (stdout). Errors, warnings, and (additional) info(rmation) are written to standard error (stderr). Errors stop the program run. Errors, warnings, and infos are of the form::
routine: Error message.
routine: Warning! Warning message.
routine: Info! Info message.
respectively, where routine is the name of the subroutine where the error (etc.) has occurred. An error message that ends on ... (bug?) indicates a possible bug in the code (please inform the developers).
It is recommendable to pipe the output to a file (in Bash)
Pipes stdout to spex.out and stderr to the screen::
$ spex > spex.out
Pipes stdout and stderr to spex.out::
$ spex &> spex.out
Pipes stdout to spex.out and stderr to spex.err::
$ spex > spex.out 2> spex.err
Depending on the job type and keywords, there are additional output files containing, for example, the resulting spectra. These output files can be in ASCII and binary format. Further details are given in the :ref:`tutorials`.
This diff is collapsed.
.. _tutorials:
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