Polarizabilities and Optical Rotations

The calculation of dynamic polarizabilities is controlled by the keyword

$\parbox{0.5\textwidth}{\raggedright\texttt{\$scfinstab dynpol} \textit{unit \\ list of frequencies} \ }$

unit specifies the unit of the following frequencies and may be ev, nm, 1/cm, or a.u. (default). The frequencies may be either purely real or purely imaginary. For example, to calculate dynamic polarizabilities at 590nm and 400i nm (i is the imaginary unit), specify

$scfinstab dynpol nm
  590
  400 i

and run ESCF,

escf > escf.out &

        .

The resulting polarizabilities and rotatory dispersions are given in a.u. in the program output (escf.out in the above example). For conversion of the optical rotation in a.u. to the specific rotation in deg$\cdot$[dm$\cdot$(g/cc)]$^{-1}$ see Eq. (15) of ref. [75].

Note that convergence problems may occur if a frequency is close to an electronic excitation energy. This is a consequence of the (physical) fact that the response diverges at the excitation energies, and not a problem of the algorithm.

Static polarizabilities are calculated most efficiently by specifying

$scfinstab polly

before starting ESCF.