#! /bin/sh

# By default in ADF the electron density at the nuclei is calculated, no input
# key is required. The electron density at the nuclei could be used for the
# interpretation of isomer shifts in Mossbauer spectroscopy. The absolute
# electron density at a nucleus heavily depends on the accuracy of the basis set
# in the core region of this nucleus, especially if relativistic effects are
# included. Important is to use the same basis set, same exchange correlation
# functional, same numerical accuracy, if electron densities at nuclei in
# different molecules are compared. For the calculation of Mossbauer quadrupole
# splittings the key QTENS is required For 57 Fe quadrupole splittings will be
# written in units of mm/s, used in Mossbauer spectroscopy Example shows a
# calculation on ferrocene with anon-relativistic, and two with a scalar
# relativistic ZORA Hamiltonian using a different all electron basis set.

# First a non-relativistic calculation.

$ADFBIN/adf <<eor
title ferrocene

Atoms
    FE        0.000000    0.000000    0.000000
    C         1.215650    0.000000    1.600813
    C         0.375656   -1.156152    1.600813
    C        -0.983481   -0.714541    1.600813
    C        -0.983481    0.714541    1.600813
    C         0.375656    1.156152    1.600813
    C         1.215650    0.000000   -1.600813
    C         0.375656    1.156152   -1.600813
    C        -0.983481    0.714541   -1.600813
    C        -0.983481   -0.714541   -1.600813
    C         0.375656   -1.156152   -1.600813
    H         2.310827    0.000000    1.629796
    H         0.714085   -2.197727    1.629796
    H        -1.869498   -1.358270    1.629796
    H        -1.869498    1.358270    1.629796
    H         0.714085    2.197727    1.629796
    H         2.310827    0.000000   -1.629796
    H         0.714085    2.197727   -1.629796
    H        -1.869498    1.358270   -1.629796
    H        -1.869498   -1.358270   -1.629796
    H         0.714085   -2.197727   -1.629796
End

xc
 gga blyp
end

Basis
     Type TZP
     Core none
End

qtens

NumericalQuality Good
exactdensity

eor


# Next the scalar relativistic ZORA calculations. ADF will also calculate the
# quadrupole splittings including the small component density, also called SR
# ZORA-4.


$ADFBIN/adf <<eor
title ferrocene

Atoms
    FE        0.000000    0.000000    0.000000
    C         1.215650    0.000000    1.600813
    C         0.375656   -1.156152    1.600813
    C        -0.983481   -0.714541    1.600813
    C        -0.983481    0.714541    1.600813
    C         0.375656    1.156152    1.600813
    C         1.215650    0.000000   -1.600813
    C         0.375656    1.156152   -1.600813
    C        -0.983481    0.714541   -1.600813
    C        -0.983481   -0.714541   -1.600813
    C         0.375656   -1.156152   -1.600813
    H         2.310827    0.000000    1.629796
    H         0.714085   -2.197727    1.629796
    H        -1.869498   -1.358270    1.629796
    H        -1.869498    1.358270    1.629796
    H         0.714085    2.197727    1.629796
    H         2.310827    0.000000   -1.629796
    H         0.714085    2.197727   -1.629796
    H        -1.869498    1.358270   -1.629796
    H        -1.869498   -1.358270   -1.629796
    H         0.714085   -2.197727   -1.629796
End

xc
 gga blyp
end

Basis
     Type TZP
     Core none
End

qtens

relativistic scalar zora
NumericalQuality Good
exactdensity


eor


# Next a scalar relativistic calculation is performed with a much larger basis
# set (QZ4P) in the core region. Changing the basis set will have a large effect
# on the electron density at the nucleus and a noticeable effect on the
# calculated quadrupole splittings.


$ADFBIN/adf <<eor
title ferrocene

Atoms
    FE        0.000000    0.000000    0.000000
    C         1.215650    0.000000    1.600813
    C         0.375656   -1.156152    1.600813
    C        -0.983481   -0.714541    1.600813
    C        -0.983481    0.714541    1.600813
    C         0.375656    1.156152    1.600813
    C         1.215650    0.000000   -1.600813
    C         0.375656    1.156152   -1.600813
    C        -0.983481    0.714541   -1.600813
    C        -0.983481   -0.714541   -1.600813
    C         0.375656   -1.156152   -1.600813
    H         2.310827    0.000000    1.629796
    H         0.714085   -2.197727    1.629796
    H        -1.869498   -1.358270    1.629796
    H        -1.869498    1.358270    1.629796
    H         0.714085    2.197727    1.629796
    H         2.310827    0.000000   -1.629796
    H         0.714085    2.197727   -1.629796
    H        -1.869498    1.358270   -1.629796
    H        -1.869498   -1.358270   -1.629796
    H         0.714085   -2.197727   -1.629796
End

xc
 gga blyp
end

Basis
     Type QZ4P
     Core none
End

qtens

relativistic scalar zora
NumericalQuality Good
exactdensity


eor