Example: NMR Spin-spin coupling constants, hybrid PBE0: HF¶
A calculation of NMR nuclear spin-spin coupling constants (NSCCs) for the hybrid PBE0.
The hybrid PBE0 is chosen as exchange-correlation potential in the ADF calculation. The key ‘usespcode’ is required for consistency reasons of the PBE0 implementation in ADF and the kernel that is used in the ‘CPL’ program, that calculates NMR spin-spin coupling constants. Symmetry should be NOSYM. The basis sets used are specially optimized all-electron basis sets for NMR spin-spin coupling calculations (in the directory $ADFHOME/atomicdata/ZORA/jcpl), which have extra tight functions, compared to a default ADF basis set. The integration accuracy is extra high (Quality VeryGood).
$ADFBIN/adf <<eor
UNITS
length Angstrom
angle Degree
END
:: experimental bond length
ATOMS
F 0.0000 0.0000 0.0000
H 0.0000 0.0000 0.9170
END
BASIS
Type ZORA/jcpl
Core None
END
usespcode
XC
hybrid PBE0
END
SYMMETRY nosym
SCF
converge 1.0e-8 1.0e-6
END
BeckeGrid
Quality verygood
end
scf
converge 1e-8 1e-7
end
end input
eor
The first call to cpl is as follows:
$ADFBIN/cpl <<eor
gga
nmrcoupling
dso
pso
scf convergence 1e-6 iterations 20
nuclei 1 2
end
endinput
eor
The key ‘gga’ is included to use the first-order GGA potential instead of the first-order VWN potential. The Hartree-Fock part of the kernel is included automatically if a hybrid potential is used in the ADF calculation.
The second CPL run also includes the spin-dipole (SD) term, through the SD subkey, which is much more time-consuming.
sd