Example: NMR Spin-spin coupling constants, finite nucleus: PbH4

Download PbH4_finitenuc.run

Example for a finite nucleus calculation and the calculation of NMR spin-spin coupling constants.

One of the quality-determining factors for the calculation of NMR coupling constants is the chosen basis set, especially one needs enough tight s functions. If one has a large enough basis set in the core region one can see an effect of using a finite size of the nucleus instead of a point nucleus, especially for heavy nuclei. Such large basis sets can be found for some elements in $ADFRESOURCES/ZORA/jcpl, which are basis sets especially designed for NMR spin-spin coupling calculations. In this example first a basis set for Pb is made which has many tight s functions.

cat < eor  $PWD/Pb
Pb Basis TZ2P - all steep, plus high exponent fcts.

BASIS
 1s    39358.2303582207
 1s    20080.7297746024
 1s    10245.2702931645
 1s    5227.17872100229
 1s    2666.92791887872
 1s    1360.67750963200
 1s    694.223219200000
 1s    354.195520000000
 1s    180.712000000000
 2p    39358.2303582207
 2p    20080.7297746024
 2p    10245.2702931645
 2p    5227.17872100229
 2p    2666.92791887872
 2p    1360.67750963200
 2p    694.223219200000
 2p    354.195520000000
 2p    180.712000000000
        1S   92.200
        2S  106.000
        2S   40.200
        3S   51.150
        3S   21.850
        4S   13.400
        4S    9.550
        5S    7.650
        5S    5.200
        6S    3.700
        6S    2.400
        6S    1.580
        2P  196.000
        2P   70.200
        2P   38.300
        3P   21.750
        3P   15.900
        4P   14.500
        4P    9.900
        5P    6.600
        5P    4.200
        6P    2.700
        6P    1.600
        6P     .960
        3D   29.400
        3D   18.800
        4D   13.000
        4D    8.450
        5D    6.000
        5D    3.650
        5D    2.200
        4F   17.560
        4F    9.950
        4F    5.750
        6D    1.600
        5F    2.500
END

CORE   0 0 0 0
END
eor

This large basis set for Pb is used in ADF calculations on PbH4 and the calculation of the NMR spin-spin coupling constants.

$ADFBIN/adf <<eor
UNITS
    length Angstrom
    angle Degree
END
NuclearModel Gaussian
Print Nuclei
ATOMS
 Pb      0.000000      0.000000      0.000000
  H     -1.023703      1.023703      1.023703
  H      1.023703     -1.023703      1.023703
  H     -1.023703     -1.023703     -1.023703
  H      1.023703      1.023703     -1.023703
END
BASIS
type DZP
core None
Pb $PWD/Pb
END
XC
 gga PBE
END
usespcode
SCF
iterations 100
converge 1.0e-8 1.0e-6
END
BeckeGrid
 quality verygood
End
relativistic scalar zora
end input
eor

$ADFBIN/cpl <<eor
gga
Print Nuclei
nmrcoupling
scf convergence 1e-5 iterations 25
 nuclei 1 2
end
endinput
eor