Example: Hyperpolarizabilities of He and H2¶
This sample illustrates the computation of (hyper) polarizability tensors for the He atom and the H2 molecule.
The symmetry is specified, because the Response module in ADF cannot yet handle the infinite symmetries ATOM, C(lin), D(lin).
$ADFBIN/adf <<EOR Title expt geometry H2(VII),VWN noprint sfo,frag,functions Symmetry C(8v) Atoms H 0 0 -0.37305 H 0 0 0.37305 End Fragments H t21.H7 End Response HyperPol 0.03 DynaHyp AllComponents End EField 0 0 0.001 NumericalQuality Good end input EOR
The Response data block specifies (AllComponents) that not only the (default) zz-dipole polarizability is to be computed, but the complete tensor. The subkey HyperPol instructs the program to compute hyper*polarizabilities and not only polarizabilities. The DynaHyp subkey implies that the *frequency-dependent (hyper)polarizability is calculated. In that case the main laser frequency has to be specified, in hartree units, after the HyperPol subkey.
Only the first hyperpolarizability has been implemented in ADF. Some information on second hyperpolarizabilities can be obtained from the calculation of the first one in a finite field (EFIELD).
In similar fashion the frequency-dependent hyperpolarizability is computed for He, but only the zzz-component because now the AllComponents subkey is omitted.
$ADFBIN/adf <<EOR Title hyperpolarizability He with the LB94 potential noprint sfo,frag,functions Atoms He 0 0 0 End XC GGA LB94 END Fragments He t21.He8 End Response HyperPol 0.07 DynaHyp End NumericalQuality Good EField 0 0 0.001 Symmetry C(8v) end input EOR