DFTB

Perform a DFTB calculation

SCC

The self-consistent charge variant of DFTB. The default is non-SCC.

MEMOSCC

use previous atomic charges to restart the SCC process at a new geometry. This keyword automatically set SCC calculation (even without SCC keyword)

TOL=

The SCC convergence criterion in electron charges. The default is 1.0E-8.

MAX=

Maximum number of SCC cycles. The default is 100

MIX=

Mixing value for simple and Broyden mixing. The default is 0.2. This value is independent from the DFT mixing value

SIMPLE

Simple mixing instead of Broyden convergence acceleration is performed for SCC. This is per default switched off

L-DEP

Angular momentum resolved SCC. Here, the self-consistent charge procedure is applied to Mulliken shell charges rather than to Mul- liken atomic charges.By default, this option is deactivated.

FERMI=

As FERMI, but with used-specified Fermi temperature (in K) following the keyword.

FERMI

The electron occupation follows a Fermi distribution

DISP=

London dispersion with a damping function. By default this option is switched off. DISP=1 Zhechkov et al., JCTC 2005 DISP=2 : Rapacioli et al., JCP, 2009

DISP

Equivalent to DISP=1. By default this option is switched off.