Next: Examples of input command
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The input command file consists of separate lines each containing
- -
- a label
- -
- a label followed by a character, integer and/or fix-point or
- -
- a character, integer and/or fix-point constant.
Note that
- -
- labels can be in upper or lower case,
- -
- compulsory labels, i.e. these that must be included in the input
command file, are marked ``
'' and the optional
ones ``
'',
- -
- the compulsory labels must follow the order given below;
the optional ones can be inserted anywhere between title
and stop labels,
- -
- optional parameters are enclosed in square brackets,
- -
denotes a fix-point constant,
- an integer,
- a string
of characters,
- -
- exclamation mark placed anywhere in an input line starts a comment;
what follows "!" is ignored.
The following labels can be used:
- $&bull#bullet;$
- TITLE
- Format:
- title
is any string of up to 80 characters describing the current
case. This string is used as a header of disk output files containing
orbitals and potentials.
- $&bull#bullet;$
- METHOD
- Format:
- method
Select the type of calculation.
:
- HF - Hartree-Fock method
:
- HFS - Hartree-Fock-Slater method
:
- OED - One Electron Diatomic states
- $&bull#bullet;$
- NUCLEI
- Format:
- nuclei
Set the nuclei charges and the bond length.
:
- nuclear charge of centre A (integer)
:
- nuclear charge of centre B (integer)
:
- bond length (real)
:
- the internuclear separation can be given in
angstrom units if this string is included (the conversion factor
0.529177249 is used)
If
then the molecule is considered to be a
homonuclear one (this threshold can be changed by redefining HOMOLEVL variable in blk_data.inc.raw).

- HOMO
- Format:
- homo
This label is used to impose explicitly
symmetry upon orbitals
of homonuclear molecules in order to improve scf/sor convergence.

- BREAK
- Format:
- break
When this label is present homonuclear
molecules are calculated in
symmetry and the
symmetry labels (u or g) are superfluous
(see below).
- $&bull#bullet;$
- CONFIG
- Format:
- config
:
- the total charge of a system
The following cards define molecular orbitals and their occupation.
Note that the last orbital description card must contain an extra
label
.
The possible formats are:
- Format:
:
- number of fully occupied orbitals of a given irreducible
representation (irrep) of the
group;
2 electrons make
orbitals fully occupied
and 4 electrons are needed for filling the orbitals belonging to the
other irreps
:
- symbol of the
irrep to which the orbitals
belong (sigma, pi, delta or phi)
- Format:
-
:
- number of fully occupied orbitals of a given irrep of the
group
:
- symbol of the
irrep to which the orbitals belong
(sigma, pi, delta or phi)
:
- symbol for the inversion symmetry of the
irreps
(u or g)
Use this format for a homonuclear molecule unless break command
is included.
- Format:
-
:
- number of orbitals of a given irrep of the
group
:
- symbol for the
irreps to which the
orbitals belong (sigma, pi, delta, phi)
-
:
or . (a dot);
denotes spin up/down
electron and . denotes an unoccupied spin orbital
- Format:
-
:
- number of orbitals of a given irrep of the
group
:
- symbol for the
irrep to which the
orbitals belong (sigma, pi, delta, phi)
:
- symbol for the inversion symmetry of the
irrep (u or g)
-
:
or . (a dot);
denotes spin up/down
electron and . denotes an unoccupied spin orbital

- GRID
Two possible formats are (the second one is retained for the backward
compatibility):
- Format:
- grid
An integer and a real define a single 2d grid.
:
- the number of grid points in
variable
-
:
- the practical infinity
is calculated so as to make the step size in
variable
equal to the stepsize in
variable.
and
have to
meet special conditions. If the conditions are not fulfilled the
nearest (but smaller) appropriate values are used.
- Format:
- grid
Two integers and one real define a single 2d grid.
:
- the number of grid points in
variable
:
- the number of grid points in
variable
-
:
- the practical infinity
and
have to meet special conditions. If the
conditions are not fulfilled the nearest (but smaller) appropriate
values are used.

- SUBGRID
- Format:
- subgrid
Define up to 3 subgrids.
:
- number of subgrids (integer)
:
- the number of grid points in
variable (integer)
-
:
- number of points in the
direction for each of the subgrids (integers)
-
:
- the step size in
variable for the first
subgrid (real)
:
- step sizes (reals) for other subgrids are
defined as
,
Note that either GRID of SUBGRID label must be included in the
input command file.

- INTERP
- Format:
- interp
Use this label to change the grid between separate runs of the program.
The restriction is that only the number of grid points in one of the
variables or
can be changed at a time.
- $&bull#bullet;$
- INITIAL
- Format:
- initial
:
- determine the initial source of orbitals and potentials:
:
- specifies how exchange potentials will be read/written
and manipulated (stored in memory). The program always keeps all
orbitals and Coulomb potentials in core. The exchange potentials can
also be all kept in core (if there is enough memory). However, during
a relaxation of a particular orbital only a fraction of them is in
fact needed. Thus all exchange potentials can be kept on disk as
separate files (named fort.31, fort.32, ... during a run) and only
relevant ones are being retrieved when necessary.1
- read exchange potentials as separate files and
write them back as separate files
- read all exchange potentials in a file but write
them out as separate files
- read all exchange potentials separately but write
them out as a single file
- read and write exchange potentials in the form of
a single file
:
- if
then this parameter must be set to 1 or 2. In
such a case the initialization of each of the orbitals has to be
defined in terms of the linear combination of atom centered
hydrogen-like functions. For each orbital include a card of the
following format (the order of orbitals should match the order
specified under the config label):
- Format:
-
where
- mixing coefficient for a hydrogenic orbital on the
centre (real),
- its principle quantum number (integer)
- its orbital quantum number (integer)
- the effective nuclear charge if
or
a screening parameter if
(real)
- mixing coefficient for a hydrogenic orbital on the
centre (real),
- its principle quantum number (integer)
- its orbital quantum number (integer)
- the effective nuclear charge if
or
a screening parameter if
(real)
- set to 1 to freeze the orbital during scf; otherwise
set to 0 (integer)
- a number of successive over-relaxations for a given orbital
(integer); if omitted is set to 10

- FEFIELD
- Format:
- fefield
:
- a strength of an external static electric field directed along
the internuclear axis (in atomic units)

- MULTIPOL
- Format:
- multipol
:
- if
multipole moment expansion coefficients are
recalculated when the maximum error in orbital energy is reduced by
(the default value is 1.15). To suppress recalculation of the
coefficients set
to a negative real number. This is useful when
generating potentials from a set of fixed orbitals, e.g from
GAUSSIAN94 orbitals.

- SCF
- Format:
- scf
:
- maximum number of scf iterations (default 1000);
to skip the scf step set
to a negative
integer,
:
- every
scf iterations orbitals and potentials
are saved on disk (default 100). If
functions
are saved on disk upon completion of the scf process. If
functions are never written to disk,
:
- if the maximum error in orbital energy is less than
than the scf process is terminated (the
default value is 10),
:
- if the maximum error in orbital norm is less than
than scf process is terminated (the default
is 10),
:
- the level of output during scf process
- the orbital convergence rate, orbital
energy and normalization of every orbital is printed
in every scf iteration
- the orbital convergence rate, orbital
energy and normalization of the worst converged
orbital is printed in every scf iteration (default)
- the orbital convergence rate, orbital
energy and normalization of the worst converged
orbital is printed every
iterations.
Printing of ``... multipole moment expansion
coefficients (re)calculated ...'' communique is
suppressed
Total energy is printed every
iterations.

- FIX
- Format:
- fix
If
,
or
are set to 1 then orbitals, Coulomb
potentials or exchange potentials, respectively, are kept frozen during the
scf/sor process (the respective default values are 0, 0 and 2).
If
then exchange potentials are relaxed only once during an
scf cycle.
and
cannot be set to 1 if hydrogenic
orbitals are used to initiate the orbitals.

- XALPHA
- Format:
- xalpha
If this label is present the Slater exchange approximation, i.e.
, is used and
the parameter
can be modified. This approximation is useful to
quickly improve the initial HF orbitals.
is a real number
and 0.7 is its default value.

- SOR
- Format:
- sor
Change default values of sor parameters.
:
- the number of (MC)SOR iterations (over each subgrid) for a
given function being relaxed in a single SCF cycle (the default value is 10)
:
- a scaling factor used to change
when
relaxing potentials (see RELCOUL1/2 and
RELEXCH1/2). The new value of (MC)SOR iterations is
calculalated as
/
; the default value of
is 1.
:
- if
SOR (MCSOR) method is used to solve
Poisson equations for orbitals and potentials (the default value is 1);
if
SOR method is used to solve Poisson equations for
orbitals and MCSOR - for potentials
- $&bull#bullet;$
- OMEGA
- Format:
- omega
Up to three real numbers in each line setting over-relaxation parameter
for relaxation of orbitals and potentials for each
subgrid. If the second or the third parameter is omitted, the
value for the first subgrid is used.
Note that a semiempirical formula can be used to calculate a
near-optimal value of
by specifying
as a negative real number.

- ORDER
- Format:
- order
Up to three integers defining the ordering of mesh points on subgrids.
:
- natural ordering
:
- 'middle' type of sweep (the default)

- FERMI
- Format:
- fermi
When this label is present, the Fermi nuclear charge distribution
is used.
and
define the atomic masses (in amu) of nuclei A
and B.

- GAUSS
- Format:
- gauss
When this label is present, the Gauss nuclear charge distribution
is used.
and
define the atomic masses (in amu) of nuclei A
and B.

- DEBUG
- Format:
- debug
Up to 20 different
debug flags can be set at a time. If the integer
is encountered the debug
flag
is set, i.e. idbg
.
- $&bull#bullet;$
- STOP
- Format:
- stop
This label indicates the end of input data.
Next: Examples of input command
Up: users_guide
Previous: users_guide
Jacek Kobus
2003-01-31