# Structure of the Output¶

ADF produces two ASCII files: standard output and the log file. The latter is a very concise summary of the calculation’s progress during the run. Furthermore, ADF produces and reads binary data files. Most of these files have the so-called KF format. KF stands for Keyed File: KF files are keyword oriented, which makes them easy to process by simple procedures. KF files are Direct Access binary files. Consult the Scripting Section for information about how to use some standard utilities for processing KF files.

The graphical user interface ADF-GUI provides graphical representations of calculated data fields:

## Job Characteristics on standard Output¶

• Copy of the input file, except any InLine records: these are expanded and the contents of the inlinefile replaces the InLine command in the echo.
• Header with the program name, the release number and a copyright statement.
• Directly below the header are printed the job identification, title, and any comments that may have been supplied via input (key COMMENT). The job identification is comprised of the ADF release number and the date and time of the calculation.

Main Job Characteristics

• The Model Parameters such as the Density Functional and relativistic options.
• A list of attached files: restart data files and fragment files.
• The run type: Geometry Optimization, Frequencies...
• (Initial) geometric data: atomic positions, atom types, defined fragments, and the inter-atomic distance matrix.
• The point group symmetry, with a list of the irreducible representations and subspecies.
• The electronic configuration: occupation numbers (if specified), their distribution over spin-$$\alpha$$ and spin-$$\beta$$, and the net charge of the molecule.

Build Info: Fragments and Function Sets

• Correspondence between fragments in the molecule and the corresponding master fragments on the pertaining fragment file. (This output is by default off)
• SFOs: the Symmetry combinations of Fragment Orbitals. The SFOs are the basic conceptual entities for the analysis of MOs and other results.
• The elementary basis functions and the frozen-core levels of the atoms.

Technical Parameters

• Parallelization and vectorization characteristics.
• Direct versus Store-On-Disk options.
• Update strategy parameters for the SCF procedure.
• General precision settings for numerical integration and neglect-of-small function values (in integral evaluations).

Computational Report

• Numerical integration parameter(s) and the number of generated (symmetry unique) integration points, and partitioning of the points in blocks.
• SCF procedure, at each cycle: for each irreducible representation: the one-electron orbital energies and the occupation numbers for a contiguous sequence of orbitals.
• Gross atomic charges, computed from a Mulliken population analysis.
• Property specific output, like geometry updates, spectroscopic properties.

Exit Procedure

• Normal termination or an error message.
• A list of all files that are (still) open when the exit routine is called. The program closes such files at this point.
• Information about buffered I/O processing during the calculation.
• A check of workspace to see whether all dynamically allocated arrays have been cleaned-up.
• Timing Statistics: a survey of CPU, System (I/O) and Elapsed times spend in various sections of the program.

Logfile

At the end of the calculation the log file is copied (optionally, see key PRINT) to the tail of the standard output file. The log file contains a concise summary of the run.

## Log file, TAPE21, TAPE13¶

The log file (logfile) is generated during the calculation and flushed after (almost) each message that is sent to it by the program. Consequently, the user can inspect it and see what is going on without being delayed by potentially large system I/O buffers. Each message contains date and time of the message plus additional info.

A major part of the messages simply states the name of a procedure. Such messages are sent when the procedure is entered. During the SCF procedure, the SCF errors, which are a measure for non-self-consistency, are written at every cycle. In calculations where the geometry is changing (optimization, frequencies...) each set of new coordinates is sent to the log file (Cartesian, in angstrom and also Z-matrix, if a Z-matrix structure was provided in the input file). Other messages should be self-explanatory.

Be alert on error messages. Take them seriously: inspect the standard output carefully and try to understand what has gone wrong. Be also alert to warnings. They are not necessarily fatal but you should understand what they are about before being satisfied with the results of the calculation. Do not ignore them just because the program has not aborted: in some cases the program may not be able to determine whether or not you really want to do what appears to be wrong or suspicious. If you believe that the program displays erratic behavior, then the standard output file may contain more detailed information. Therefore, in such case save the complete standard output file, together with the logfile, in case we need these files for further analysis.

TAPE21

TAPE21 is the general result file of an ADF calculation. It is a KF file: Direct-Access, binary, and keyword driven. It contains information about the calculation. You can use it as a fragment file in a subsequent calculation on a bigger molecule, where the current one may be a part, or in an analysis program. For more information on TAPE21, see Appendix on TAPE21.

TAPE13

TAPE13 is the checkpoint file for restarts after a crash. It is a concise version of TAPE21, containing only the data the program uses for restarting the calculation. See the RESTART keyword. Like TAPE21, TAPE13 is a binary, keyword driven KF file, see Appendix on TAPE13.