![\fbox{
\parbox[h][\height][l]{12cm}{
\small
\noindent
{\bf Reference literature:...
...newblock {\em J.Chem.Phys.}, {\bf 102},\hspace{0.25em}8953, (1995).
\end{list}}}](img87.png)
The necessary input for a finite-field calculation is given in the **INTEGRALS and **WAVE FUNCTIONS input modules. A typical input file for an finite field SCF calculation of the magnetizability of a molecule will be:
**DALTON INPUT .RUN PROPERTIES **INTEGRALS .DIPLEN **WAVE FUNCTIONS .HF *HAMILTONIAN .FIELD 0.003 XDIPLEN **PROPERTIES .MAGNET **END OF DALTON INPUT
In the
**INTEGRALS input module we request the evaluation of dipole
length integrals, as these correspond to
the electric dipole operator,
and will be used in SIRIUS for evaluating the interactions between the
electric dipole and the external electric field. This is achieved in
the
*HAMILTONIAN input module, where the presence of an external
electric field is signaled by the
keyword
.FIELD. On the next line, the
strength of the electric field (in atomic units) is given, and on the following
line we give the direction of the applied electric field
(XDIPLEN, YDIPLEN, or ZDIPLEN). Several fields may
of course be applied at the same time. In comparison with DALTON 1.2, the present version of DALTON can also calculate the nuclear
shielding polarizabilities with respect to an external electric field
gradient using London atomic orbitals, both using the traceless
quadrupole operator
.THETA and the second moment of charge
operator
.SECMOM.