Example: Density-Dependent Dispersion Correction (dDsC): CH4-dimer¶

#! /bin/sh


# The density-dependent dispersion energy correction, dDsC, by S.N. Steinmann
# and C. Corminboeuf, is used to calculate interactions between non-overlapping
# densities, which standard density functional approximations cannot accurately
# describe. The example is for the methane dimer.

# The 'debug dispersion' is included such that in the output one can find more
# details on the exact parameters that are used.


$AMSBIN/ams <<eor
System
  atoms
     C  -0.000959    0.000775    1.853082
     H  -0.747186    0.712608    1.489389
     H   0.987865    0.294742    1.490258
     H  -0.241511   -0.998876    1.480724
     H  -0.002970   -0.005330    2.946903
     C   0.000962   -0.000776   -1.853082
     H   0.004264    0.004684   -2.946903
     H  -0.989749   -0.289559   -1.491241
     H   0.743184   -0.716138   -1.488107
     H   0.246099    0.997870   -1.481022
  end
end

Task GeometryOptimization

GeometryOptimization
  Convergence 
    Gradients 1E-3
    Energy    0.1
    Step      0.1
  End
End

Engine ADF
  title methane-dimer
  debug dispersion
  basis
    type TZP
  end
  numericalquality good
  symmetry nosym
  xc
    dispersion DDsC
    gga Becke LYP
  end
EndEngine
eor