# Example: FDE and COSMO: H2O-NH3¶

Download LoCOSMO_H2O-NH3.run

This is example for a calculation of FDE and (localized) COSMO in ADF in case of closed shell fragments.

It performs single point runs for H2 O and NH3 in COSMO (water) and uses these fragments in a freeze-and-thaw calculations. Recommended is to limit the number of freeze-and-thaw cycles in such calculations where FDE and COSMO are combined, because the FT convergence criterion may not be met in a finite number of cycles, although the density is practically converged.

In the freeze-and-thaw cycles LoCosmo is included in the SOLVATION key, thus the local COSMO will be used in the calculation. A cutoff radius (Angstrom) must be specified after the LoCOSMO subargument, in this case it is 3.0 Angstrom. All surface charges within this radius from any atom of the active fragment are included in the active charge space.

$ADFBIN/adf << EOR Title H2O isolated ATOMS H 0.0201 0.6299 0.0000 O -0.0370 1.6130 0.0000 H 0.8936 1.9007 0.0000 END SYMMETRY NOSYM XC GGA BP86 END BASIS Type DZP END NumericalQuality Good EXACTDENSITY SOLVATION END EOR mv TAPE21 t21.iso.rho1$ADFBIN/adf << EOR
Title NH3 isolated
ATOMS
N       -0.0370  -1.4327  0.0000
H        0.8110  -2.0086  0.0000
H       -0.5850  -1.6987  0.8244
H       -0.5850  -1.6987 -0.8244
END
SYMMETRY NOSYM
XC
GGA BP86
END
BASIS
Type DZP
END
NumericalQuality Good
EXACTDENSITY
SOLVATION
END
EOR
mv TAPE21 t21.iso.rho2

Title FT cycles for H2O-NH3
ATOMS
H        0.0201   0.6299   0.0000  f=frag1
O       -0.0370   1.6130   0.0000  f=frag1
H        0.8936   1.9007   0.0000  f=frag1
N       -0.0370  -1.4327   0.0000  f=frag2
H        0.8110  -2.0086   0.0000  f=frag2
H       -0.5850  -1.6987   0.8244  f=frag2
H       -0.5850  -1.6987  -0.8244  f=frag2
END
SYMMETRY NOSYM
FRAGMENTS
frag1  t21.iso.rho1
frag2  t21.iso.rho2 type=FDE &
FDEOPTIONS RELAX
SubEnd
END
XC
GGA BP86
END
NumericalQuality Good
EXACTDENSITY
SOLVATION
CHARGED LoCOSMO 3.0
END
FDE
PW91k
RELAXCYCLES 3
END
EOR