Example: FDE NMR spin-spin coupling: NH3-H2O

Download FDE_CPL_NH3-H2O.run

This example demonstrates the calculating NMR spin-spin couplings (J coupling) in case f frozen density embedding (FDE). It performs single point runs for H2O and NH3 with PBE/(ZORA/jcpl basis) (all-electron) and uses these fragments in

  • an FDE embedding calculation calculation in which water in presence of a frozen ammonia is computed
  • first the electron density / KS orbitals with ADsF
  • then the NMR J couplings with CPL (scalar code branch)
  • a corresponding FDE freeze-thaw calculation followed by calculation of NMR J couplings with CPL
  • scalar, then spin-orbit code branch

First NH3 with PBE and an all electron TZP basis set. No cpl calculation for NH3, thus regular basis is OK. This is not shown. Next H2O with PBE and an all electron ZORA/jcpl basis set:

$ADFBIN/adf << eor
a Title H2O PBE/(ZORA/jcpl) single point
 ATOMS
  O        1.56850        0.10589        0.00001
  H        0.60674       -0.03396       -0.00063
  H        1.94052       -0.78000        0.00022
 END
 SYMMETRY NOSYM
 BASIS
  Type ZORA/jcpl
  Core None
 END
 XC
  GGA PBE
 END
 NumericalQuality Good
 EXACTDENSITY
 EPRINT
  SFO NOEIG NOOVL NOORBPOP
  SCF NOPOP
 END
 NOPRINT BAS FUNCTIONS
end input
eor
mv TAPE21 t21.water

Next NH3-H2O is calculated: FDE calculation of H2O in presence of frozen NH3.

$ADFBIN/adf << eor
 Title NH3-H2O PBE/PW91k/(ZORA/jcpl) FDE single point calculation (no freeze-thaw)
 ATOMS
  O        1.56850        0.10589        0.00001    f=frag1
  H        0.60674       -0.03396       -0.00063    f=frag1
  H        1.94052       -0.78000        0.00022    f=frag1
  N       -1.39559       -0.02156        0.00004    f=frag2
  H       -1.62981        0.96110       -0.10622    f=frag2
  H       -1.86277       -0.51254       -0.75597    f=frag2
  H       -1.83355       -0.33077        0.86231    f=frag2
 END
 SYMMETRY NOSYM
 FRAGMENTS
  frag1  t21.water
  frag2  t21.ammonia type=FDE
 END
 XC
  GGA PBE
 END
 NumericalQuality Good
 EXACTDENSITY
 SAVE TAPE10
 EPRINT
 SFO NOEIG NOOVL NOORBPOP
 SCF NOPOP
 END
 NOPRINT BAS FUNCTIONS
 FDE
  PW91k
 END
eor

Finally, the calculation of the NMR spin-spin coupling of J(O-H) in water H bond-donor.

$ADFBIN/cpl << eor
 GGA
 NMRCoupling
  fc
  dso
  pso
  AtomPert 1
  AtomResp 2
  scf iterations 15 converge 1.0e-05
 End
eor

The second FDE calculation is NH3-H2O FDE calculation with 1 freeze-thaw cycle. The difference with the previous FDE calculations is:

FRAGMENTS
 frag1  t21.water
 frag2  t21.ammonia type=FDE  &
    fdeoptions RELAX
 SubEnd
END
FDE
 PW91k
 RELAXCYCLES 1
END

The calculation of the NMR spin-spin coupling of J(O-H) in water H bond-donors, no sd term.

$ADFBIN/cpl << eor
 GGA
 NMRCoupling
  fc
  dso
  pso
  AtomPert 1
  AtomResp 2
  scf iterations 15 converge 1.0e-05
 End
eor

The calculation of the NMR spin-spin coupling of J(O-H) in water H bond-donors, includes sd term.

$ADFBIN/cpl << eor
 GGA
 NMRCoupling
  fc
  sd
  dso
  pso
  AtomPert 1
  AtomResp 2
  scf iterations 15 converge 1.0e-05
 End
eor