4.1 List of Keys

Next follows the list of keys with an explanation of their meaning and the appropriate way to use them. Most keys are of the simple (record-) type. Block type keys are indicated in the list by the phrase 'block type' between brackets after the key.

For the large majority of keys, their occurrence in input is optional. Omission leads to default values and default settings. A few keys must be given however, so as to define the system to be computed. These keys are Title, Lattice, Atoms and AtomType containing the Dirac and FitFunctions subkeys; they specify respectively the title of the job, the Bravais lattice, the nuclear positions and basic characteristics of the atom type, including the auxiliary (fit) functions used to compute the Coulomb potential.

If you inspect the source code you may notice that there are in fact more keys defined in the program than those enumerated in the list below. With an eye on future developments we have omitted in this documentation a discussion of keys that will be removed or changed and that have not much practical importance anyway.

The first list of keys below contains the most important ones. The second contains keys that you will probably not use very frequently as they relate to debugging, tests, and data organization inside the program, rather than to physical or methodological aspects. Most keys in this section are block keys that contain fine-tuning options for certain aspects of the code (e.g. screening, k-space integration, SCF behavior). A third list is added. This contains only undocumented (currently existing) development/debug keys and keys that existed in the previous versions (obsolete keys).