------------------------------------------------------------------------ derivative data groups '$drvopt, $drvtol' ------------------------------------------------------------------------ option | status | description : ------------------------------------------------------------------------ crt | T | CARTESIAN 1st derivatives sec | T | CARTESIAN 2nd derivatives bas | F | energy derivatives with respect to | | BASIS SET exponents/scaling factors/ | | contraction coefficients glb | F | energy derivative with respect to | | a GLOBAL scaling factor dip | T | cartesian 1st derivatives of DIPOLE MOMENT pol | T | nuclear contribution to POLARIZABILITY fa | F | SPECTROSCOPIC ANALYSIS only tol 0.100D-06 derivative integral cutoff ------------------------------------------------------------------------ use <opt> for enabling, -<opt> for disabling of logical switches <&> will bring you back to GENERAL MENU without more changes <RETURN> OR * OR q(uit) WILL TERMINATE THIS MENUThe handling of these options is very simple. With the exception of

`tol`

, all are logical switches which are either true (or on,
active) or false (or off, inactive). You can switch between the two
states if you enter, for example, `crt`

(to switch calculation of
Cartesian first derivatives on) or `-crt`

(to switch it off). The
options `crt`

, `sec`

and `bas`

should provide no
problems. `glb`

refers to a global scaling factor for all basis
set exponents. Imagine that you would like to replace your basis set,
which contains basis functions
χ_{μ} = (x - x_{0})^{l}(y - y_{0})^{m}(z - z_{0})^{n}exp - η_{μ}(r - r_{0})^{2} |

by another basis set which contains basis functions

χ_{μ} = (x - x_{0})^{l}(y - y_{0})^{m}(z - z_{0})^{n}exp - αη_{μ}(r - r_{0})^{2} |

where

`glb`

you are able to calculate
analytical derivatives of the total energy with respect to
`dip`

enables you to calculate the first derivatives of the
electric dipole moment with respect to nuclear displacements which
gives you infrared intensities. `pol`

allows you to calculate the
contribution of the nuclear rearrangement on the electric
polarizability. `fa`

finally performs only a frequency analysis
which means that `aoforce` will read the force constant matrix
(`$hessian` or `$hessian (projected)`), diagonalize it and
give you the frequencies and normal modes. `tol`

is not a logical
switch as the other options in this menu, but a cutoff threshold for
the derivative integrals, i.e. integrals below this threshold will be
neglected in the derivative calculations.

Entering `*`

will bring you to the second derivative submenu.