Halogen bond correction for the semiempirical method PM6. The method is described in ref. [1] but newer parameters for PM6-D3H4X combination published in ref. [2] are used.
The interface implements a single unnamed method; 'method' keyword not necessary
The following examples, along with all other files needed to run them, can be found in the directory cuby4/interfaces/x_bond/examples
#=======================================================================
# X-bond correction example 1
#=======================================================================
# Geometry optimization of a halogen-bonded complex of bromobenzene with
# acetone using the PM6-D3H4X method (PM6 with empirical corrections
# for dispersion, hydrogen bonds and halogen bonds)
# Optimization setup
job: optimize
opt_quality: 0.1
optimizer: rfo
# PM6 in mopac
method: pm6
interface: mopac
mopac_precise: yes # For such optimization, accurate gradients are needed
# The corrections: D3, H4 and X
modifiers: dispersion3, h_bonds4, x_bond
# The geometry is taken from the X40 dataset, entry #20
geometry: X40:20