Example: PIM: polarizability N2 on silver cluster Ag68¶
Expert option
This example demonstrates how to do calculate static and frequency dependent polarizabilities with the Polarizability Interaction Model (PIM). The example consists of 3 calculations: static polarizability, frequency dependent, and with inclusion of effect of the local field.
When the molecule interacts with a metal nanoparticle, there are two types of interactions: the image field and the local field. The image field is caused by the dipoles induced into the nanoparticle by the molecule’s electron density. This is always taken into account in a DIM/QM calculation. The local field arises by direct interactions of the nanoparticle with an external field. Addition of the LOCALFIELD key causes the DIM/QM calculation to include this effect, but by default this is not included in a DIM/QM calculation.
Static polarizability
$ADFBIN/adf << eor
TITLE PIM Static Polarizability, N2 on Ag68
ATOMS
N -0.000006 -0.000060 2.302488
N 0.000019 0.000041 3.408628
END
BASIS
type TZP
core none
END
SYMMETRY NOSYM
SCF
Converge 1e-6
END
INTEGRATION 6 6 6
XC
GGA Becke Perdew
END
AORESPONSE
ALDA
END
DIMQM
PIM
ALGORITHM BRUTE
END
DIMPAR
Ag
rad 1.4445
drude 9.2 0.17 eV
bound 5.0
SUBEND
XYZ
68
Ag -1.2626801699 -1.1212553334 -7.5641602542
Ag 1.8701101821 -2.1177433283 -0.4836551986
...
SUBEND
END
eor
Frequency dependent polarizability
Difference in the input with respect to static polarizability:
$ADFBIN/adf << eor
TITLE PIM Frequency-Dependent Polarizability, N2 on Ag68
AORESPONSE
:: The FREQUENCY is at the Plasmon Max
FREQUENCY 1 3.55 eV
LIFETIME 0.0036749
ALDA
END
DIMQM
PIM
ALGORITHM BRUTE
:: Frequency-Dependent
FREQUENCY
END
eor
Frequency dependent polarizability including local field effect
Difference in the input with respect to static polarizability:
$ADFBIN/adf << eor
TITLE PIM Frequency-Dependent Polarizability with Local Fields, N2 on Ag68
AORESPONSE
:: The FREQUENCY is at the Plasmon Max
FREQUENCY 1 3.55 eV
LIFETIME 0.0036749
ALDA
END
DIMMQM
PIM
ALGORITHM DIRECT
:: Frequency-Dependent
FREQUENCY
:: Include the local field effects
LOCALFIELD
END