If the subkey CDSPECTRUM is included in the key EXCITATIONS the rotatory strengths for the calculated excitations are calculated, in order to simulate Circular Dichroism (CD) spectra [80,81]. Interesting for chiral molecules. This subkey should not be used in case of spin-orbit coupling. For accuracy reasons you should also use the subkey ANALYTIC in the block key EXCITATIONS, otherwise the results may be nonsense.
If the subkey ANALYTIC is included the required integrals for the CD spectrum are calculated analytically, instead of numerically. Only used in case of CD spectrum.
If the subkey VELOCITY is included ADF calculates the dipole-velocity representation of the oscillator strength. If applicable (use of subkey CDSPECTRUM) the dipole-velocity representation of the rotatory strength is calculated. Default the dipole-length representation of the oscillator strength and rotatory strength is calculated.