Using the database: BasisDefaults

BasisDefaults (block-type)

This key allows you to generate automatically the required AtomType blocks (i.e. basis and fit sets) from the database. The database is located in "$ADFHOME/atomicdata/Band". You can always see what has been generated at the beginning of the output file, where your input is echoed with the AtomType blocks expanded. It shows as a comment from which file each AtomType has been copied.

! --- basis from file /path/to/TZ2P/C.1s---

AtomType C
....
End
! --- basis from file /path/to/DZ/H---

AtomType H
....
End

The block has the following sub keys.

BasisType

The following basis sets are available.

• DZ: Double zeta. Adapted from the ADF basis set of the same name. The smallest basis set.
  The results are most likely not so accurate
• V: the original band basis set. Similar to the TZ2P basis set.
• TZ2P: Adapted from the ADF basis set of the same name. This is a good basis set.
• QZ4P: Quadruple zeta plus quadrupole polarization. The biggest basis set. For benchmark purposes only.

If you have a large unit cell, you could start with the DZ basis, to see if it will be feasible at all. For reliable results, use the V or the TZ2P basis. You can override the defaults per type by specifying Atoms%Core and Atoms%BasisType, or Atoms%Path (sub)keys.

Core

This influences the size of the frozen core used. Possible values are "None", "Small", "Medium", "Large". You should be aware that a change of this parameter does not necessarily mean that a different frozen core is used. You can again check in the output what file was really used. You can see it from the extension in the comment line preceding the AtomType key

! --- basis from file /path/to/TZ2P/C.1s---

or from the Dirac block in the AtomType key.