Keywords for wave function analysis and generation of plotting data

`dscf -proper`

(or `ridft -proper`

). In case of
Functionalities of analyses are driven by the following keywords.

`$mvd`-

leads to calculation of relativistic corrections for the SCF total density in case of`dscf`and`ridft`, for the SCF+MP2 density in case of`rimp2`and`mpgrad`and for that of the calculated excited state in case of`egrad`. Quantities calculated are expectation values and the Darwin term ( ). `$moments`-

yields calculation of electrostatic moments arising from nuclear charges and total electron densities. Also without setting this keyword moments up to quadrupole are calculated, with respect to reference point (0,0,0). Supported extensions:$moments <i> x1 y1 z1 x2 y2 z2 . .

By integer*i*; the maximum order of moments is specified, maximum and default is =3 (octopole moments), real numbers allow for the specification of one or more reference points. `$pop`-

drives the options for population analyses. By default a Mulliken PA in the basis of cartesian atomic orbitals (CAOs) is performed for the total density ( ) leading to Mulliken (brutto) charges and, in case of spin-unrestricted calculations also for the spin density ( ) leading to Mulliken (brutto) numbers for unpaired electrons. Besides total numbers also contributions from -, -, ...functions are listed separately.*Two-component wavefunctions*(only module`ridft`and only if`$soghf`

is set): In two-component calculations instead of is written to the output. Additionally a vector-file named`spinvec.txt`

is written, which includes the resulting spinvector for each atom in the system (also the direction).The following modifications and extensions are supported, if the respective commands are written in the same line as

`$pop`

:`lall`- Additional information about (and analogous for and functions) is displayed (lengthy output).
`atoms`*list of atoms*-

Contributions are plotted only if arising from atoms selected by list. `thrpl=`*real*-

Contributions smaller than`thrpl`

are not displayed (default: 0.01). `overlap`- Mulliken atomic overlap matrix is displayed.
`netto`- Mulliken netto populations (diagonal elements of Mulliken overlap matrix) are calculated.
`mosum`*list of MOs*-

Summed Mulliken contributions for a group of molecular orbitals defined by numbers referring to the numbering obtained e.g. from the tool`eiger`

. Note that occupancy of MOs is ignored, i.e. all orbitals are treated as occupied. `mo`*list of MOs*-

Mulliken contributions for single MOs defined by numbers (independent of whether they are occupied or not). If this option is valid, one may additionally set`dos width=`*real*`points=`*integer*-

to calculate a (simulated) density of states by broadening the discrete energy levels with Gaussians and superimposing them. The width of each Gaussian may be set by input (default: 0.01a.u.). The resolution (number of points) may be chosen automatically (default values are usually sufficient to generate a satisfactory plot) or specified by hand. The output files (`dos`

in case of RHF wave functions, and`dos_a+b`,`dos_a-b`,`dos_alpha`,`dos_beta`; for UHF cases) contain energies (first column), resulting DOS for the respective energy (second column) as well as -, -, -contributions for the respective energy (following columns).

$pop mo 23-33 dos atoms 2,3,7-8

leads to Mulliken PA (CAO-basis) for each of the eleven MOs`23-33`

, regarding only contributions from atoms`2-3`

and`7-8`

(results are written to standard output) and generation of file(s) with the respective simulated density of states. `$pop nbo`-

to perform a natural population analyses [117]. The possible options (specified in the same line) are

Example:`idbgl=`*integer*Debug level.`AOmust be provided, the CAO case is notimplemented.``tw=`*real*Threshold t to circumvent numericaldifficulties incomputing O

(default: tw=1.d-6).`idbgl=`*integer*Debug level

(default: idbgl=0).`abFor UHF cases: Print alpha and beta density results.``shortPrint only natural electron configuration and summary.`$pop nbo AO ab short atoms 1,2,6

leads to a natural population analysis (AO-basis) with printing the results of alpha and beta densities (only the electron configuration and the summary) for the atoms 1,2 and 6.To change the NMB set for atoms, one has to add a $nbonmb-block in the

*control*file. Example:$nbonmb ni s:4 p:2 d:1 o s:2 p:1

leads to a NMB set for Ni of 4 s-, 2 p- and 1d-functions and for O of 2 s- and 1 p-functions. `$pop paboon`-

to perform a population analyses based on occupation numbers [118] yielding "shared electron numbers (SENs)" and multicenter contributions. For this method always the total density is used, i.e. the sum of alpha and beta densities in case of UHF, the SCF+MP2-density in case of MP2 and the GHF total density for (two-component-)GHF.The results of such an analysis may depend on the choice of the number of modified atomic orbitals ("MAOs"), which can be specified by an additional line; without further specification their number is calculated by the method "mix", see below. Note: One should carefully read the information concerning MAOs given in the output before looking at the numbers for atomic charges and shared electron numbers.

`$mao selection`*options*-

to specify how MAOs are selected per atom.Available options are:

a) for the way of sorting MAOs of each atom:

`eig`-

MAOs are sorted according to their eigenvalue (those with largest EW finally are chosen). This is the default. `occ`-

MAOs are sorted according to their occupation; note that the number of all occupation is NOT the number of electrons in the system. This option is kept rather for historical reasons.

`fix`-

A fixed number of MAOs is taken for each atom; usually this is the number of shells up to the complete valence shell, e.g. 5 for B-Ne, 6 for Na-Mg, etc. Exceptions are Elements Sc (Y, La), Ti (Zr, Hf), V (Nb, Ta) for which not all five d-shells are included, but only 2, 3 or 4, respectively. This modification leads to beetter agreement with partial charges calculated by an ESP-fit. `thr <real>`-

All MAOs with an eigenvalue larger than`<real>`

are chosen; default is`<real>=0.1`

. This and the following two options are not valid in connection with`occ`

. `max`-

Maximum of numbers calculated from`fix`

and`thr=0.1`

is taken. `mix`-

2:1 mixture of`fix`

and`thr=0.1`

. This choice gives best agreement (statistical) with charges from an ESP-fit. It is the default choice.

`info`-

Eigenvalues and occupations for each MAO are written to output. `dump`-

Entire information about each MAO is written to output. Lenghty.

`atom 1,3-4 eig 7`

leads to choice of the 7 MAOs with largest eigenvalue at atoms 1, 3-4.

`$localize`-

enables the generation of localized molecular orbitals (LMOs) using Boys localization. By default, all occupied orbitals are included, localised orbitals are written (by default in the AO-basis) to file(s)`lmo`in case of RHF and`lalp`and`lbet`in case of UHF orbitals. Note, that LMOs usually break the molecular symmetry; so, even for symmetric cases the AO (not the SAO) basis is used for the output. The localized orbitals are sorted with respect to the corresponding diagonal element of the Fock matrix in the LMO basis. In order to characterize these orbitals, dominant contributions of (canonical) MOs are written to standard output as well as results of a Mulliken PA for each LMO (for plotting of LMOs see option`$pointval`

).The keyword allows for following options (to be written in the same line):

`mo`*list of MOs*-

Include only selected MOs (e.g. valence MOs) in localization procedure (numbering as available from`Eiger`). `sweeps=`*integer*-

maximum number of orbital rotations to get LMOs; default value is 10000 (sometimes not enough, in particular for highly delocalised systems). `thrcont=`*real*-

lower threshold for displaying MO and Mulliken contributions (default: 0.1). `CAO`- LMOs are written to file in the CAO basis (instead of AO)

`$esp_fit`-

fits point charges at the positions of nuclei to electrostatic potential arising from electric charge distribution (also possible for two-component calculations, for UHF cases also for spin density). For this purpose the ("real") electrostatic potential is calculated at spherical shells of grid points around the atoms. By default, Bragg-Slater radii, , are taken as shell radii, for each atom the number of points is given by , the total number of points is the sum of points for each atom reduced by the number of points of overlapping spheres. Non-default shells (one or more) can be specified as follows:`$esp_fit`

`shell`

*i1 s1*`shell`

*i2 s2*

Integer numbers

*i*define the number of points for the respective shell, real numbers*s*constants added to radii (default corresponds to one shell with s=1.0).A parametrization very close to that by Kollman (U.C. Singh, P.A. Kollman, J. Comput. Chem. 5(2), 129-145 (1984)) may be obtained by

`$esp_fit kollman`

Here five shells are placed around each atom with =1.4*, =0pm, 20pm, 40pm, 60pm, 80pm, and are the van-der-Waals radii of the atoms.

`$pointval`-

drives the calculation of space-dependent molecular quantities at 3D grids, planes, lines or single points. Without further specifications the values of densities are plotted on a three-dimensional grid adapted to the molecular size. Data are deposed to output files (suffix`plt`) that can be visualized directly with the gOpenMol program. In case of RHF-dscf/ridft calculations you get the total density on file`td.plt`

, for UHF-dscf/ridft calculations one gets both values for the total density ( ) on`td.plt`

and the "spin density" ( ) on`sd.plt`

. For mpgrad/rimp2 calculations one gets in the RHF case the total density (D(SCF+MP2)) on`td.plt`

and the MP2 contribution on`mp2d.plt`

and in the UHF case one obtains the total density ( ) on`td.plt`

, the "spin density" ( ) on`td.plt`

, and the respective MP2 contributions on files`mp2d.plt`

and`mp2sd.plt`

. For`egrad`

it is similar, just replace in the filenames`mp2`by`e`.Integration of density (if absolute value greater than

`eps`

) within a sphere (origin , radius ) is performed for `$pointval integrate`*x y z r eps*-

By default the origin is at (0,0,0), the radius is chosen large enough to include the whole 3D box and all contributions are regarded (

`eps=0`

).Data different from total and spin densities are generated by following (combinable) settings (to be written in the same line as statement

`$pointval`

):`pot`- leads to calculation of electrostatic potential arising
from electron densities, nuclei and--if present--constant electric fields and
point charges. The densities used for calculation of potentials are the
same as above; the respective filenames are generated from those of
densities by replacement of the "d" (for density) by a "p" (for potential).
By "
`pot eonly`

" only the electronic contribution to the electrostatic potential is calculated. `fld`- calculation of electric field. Note, that for 3D default
output format (
`.plt`, see below) only norm is displayed. Densities used are the same as above, filenames are generated from those of densities by replacement of "d" (for density) by "f" (for field). `mo`*list of MO numbers*-

calculation of amplitudes of MOs specified by numbers referring to the numbering obtained e.g. from the tool`eiger`

in the same format. The respective filenames are self-explanatory and displayed in the output. Note, that also in MP2 and excited state calculations the HF/DFT ground state orbitals are plotted (and not natural MP2/excited orbitals).*Two-component cases*: The density of the spinors specified by numbers referring to the numbering obtained e.g. from the file`EIGS`

are visualized. By setting the keyword`minco`

also the amplitudes of the spinor-parts are calculated, whose weights (the probability of finding the electron in this part) lie above the threshold. `lmo`*list of LMO numbers*-

calculation of amplitudes of LMOs (previously generated by`$localize`) ordered by the corresponding diagonal element of the Fock matrix in the LMO basis. `nmo`*list of NMO numbers*-

calculation of amplitudes of NMOs (previously generated by`$natural orbitals file=natural`and`$natural orbital occupation file=natural` `dens`- has to be set, if additionally to one of the above quantities also the density is to be computed.

Output formats may be specified by e.g.

`fmt=xyz`

if written to the same line as`$pointval`

. Supported are:`xyz`- in case of scalars (density, (L)MO amplitudes,
electrostatic potential) this format is:
. In case of
vectors components of the vector and its norm are displayed. This format
is valid for all types of grid (3D, plane, line, points, see below),
it is the default format in case of calculation of values at single
points. Output file suffix is
`.xyz`

. `plt`- only for 3D, default in this case. Data are written to
binary files that can be directly read by gOpenMol. Note, that this output
is restricted to scalar quantities; thus in case of vectors (E-field) only
the norm is plotted. Output file suffix is
`.plt`

. `map`- only for 3D. Data are written to ASCII files that
can be imported by e.g. gOpenMol. Note, that this output is restricted to
scalar quantities; thus in case of vectors (E-field) only the norm is plotted.
Output file suffix is
`.map`. `txt`- a format compatible with gOpenMol for visualization of vectors . The format is .
`vec`- for planes and lines (default in these cases). In case of
a line specified by
(see below) output is
for scalars, for vectors components and norm are displayed.
vectors. Analogously, in case of planes it is
. The output (file suffix
`.vec`

) may be visualized by plotting programs suited for two-dimensional plots. A command file (termed`gnuset`

) to get a contour plot by gnuplot is automatically generated. `cub`- only for 3D, writes out data in Cube format which can be imported by many external visualization programs.

For 3D grids non-default boundarys, basis vector directions, origin and resolutions may be specified as follows:

$pointval grid1 vector 0 3 0 range -2,2 points 200 grid2 vector 0 0 -7 range -1,4 points 300 grid3 vector 1 0 0 range -1,1 points 300 origin 1 1 1

Grid vectors (automatically normalised) now are ,,, the grid is centered at , and e.g. for the first direction 200 points are distributed between -2 and 2.Grids of lower dimensionality may be specified (in the same line as

`$pointval`

) by typing either`geo=plane`

or`geo=line`

or`geo=point`

The way to use is best explained by some examples:$pointval geo=plane grid1 vector 0 1 0 range -2,2 points 200 grid2 vector 0 0 1 range -1,4 points 300 origin 1 1 1

Values are calculated at a plane spanned by vectors (0,1,0) and (0,0,1) centered at (1,1,1).$pointval geo=line grid1 vector 0 1 0 range -2,2 points 50 origin 0 0 1

Values are calculated at a line in direction (0,1,0) centered at (0,0,1). Output format as above.$pointval geo=point 7 5 3 0 0 7

Values are calculated at the two points and .