$DATA group (required)
This group describes the global molecular data such as point group symmetry,
nuclear coordinates, and possibly the basis set. It consists of a series of free
format card images.
-1- TITLE a single descriptive title card :1.Zeile,
Überschrift
-2- GROUP, NAXIS: 2.Zeile, Symmetriegruppe,
Ordnung der Hauptdrehachse
GROUP is the Schoenflies symbol of the symmetry group, you may choose from
C1, Cs, Ci, Cn, S2n, Cnh, Cnv, Dn, Dnh, Dnd, T, Th, Td, O, Oh.
NAXIS is the order of the highest rotation axis, and
must
be
given
when
the
name
of the
group
contains
an N. For example, "Cnv 2" is C2v. "S2n 3" means S6. Use of
NAXIS
up to 8 is
supported in each axial
groups.
For linear
molecules,
choose
either
Cnv
or
Dnh,
and enter
NAXIS
as 4. Enter atoms
as Dnh
with
NAXIS=2.
If the electronic state of either is degenerate, check the note about the effect
of symmetry in the electronic state in the SCF section of REFS.DOC.
Armed with only the name of the group, GAMESS is able to exploit the molecular
symmetry throughout almost all of the program, and thus save a great deal of
computer time.
Cards -3- and -4- are quite complicated, and are rarely given.
A *SINGLE* blank
card
may
replace
both
cards
-3- and -4-, to select the 'master frame', which is defined on the next
page. If you choose to enter a blank card, skip to the bottom of the next page.
Note !
If
the
point group
is
C1 (no symmetry),
skip
over
cards
-3- and -4- (which
means
no blank card).
D. h. im Allgemeinen folgt nach der Symmetriezeile
eine Leerzeile, es sei denn, C1 wurde als Symmetriegruppe gewählt.
-3- X1, Y1, Z1, X2, Y2, Z2
For C1 group, there is no card -3- or -4-.
For CI group, give one point, the center of inversion.
For CS group, any two points in the symmetry plane.
For axial groups, any two points on the principal axis.
For tetrahedral groups, any two points on a two-fold axis.
For octahedral groups, any two points on a four-fold axis.
-4- X3, Y3, Z3, DIRECT
third point, and a directional parameter.
For CS group, one point of the symmetry plane, noncollinear with points 1 and 2.
For CI group, there is no card -4-.
For other groups, a generator sigma-v plane (if any) is the (x,z) plane of the
local frame (CNV point groups).
A generator sigma-h plane (if any) is the (x,y) plane of the local frame (CNH
and dihedral groups).
A generator C2 axis (if any) is the x-axis of the local frame (dihedral groups).
The perpendicular to the principal axis passing through the third point defines
a direction called D1. If DIRECT='PARALLEL', the x-axis of the local frame
coincides with the direction D1. If DIRECT='NORMAL', the x-axis of the local
frame is the common perpendicular to D1 and the principal axis, passing through
the intersection point of these two lines. Thus D1 coincides in this case with
the negative y axis.
The
'master
frame'
is
just a standard
orientation
for
the
molecule.
By
default,
the
'master
frame'
assumes
that
1. z is the
principal rotation axis (if any),
2. x is a perpendicular two-fold axis (if any),
3. xz is the sigma-v plane (if any), and
4. xy is the sigma-h plane (if any).
Use the lowest number rule that applies to your molecule.
Some examples of these rules:
Ammonia (C3v): the unique H lies in the XZ plane (R1,R3).
Ethane (D3d): the unique H lies in the YZ plane (R1,R2).
Methane (Td): the H lies in the XYZ direction (R2). Since there is more than one
3-fold, R1 does not apply.
HP=O (Cs): the mirror plane is the XY plane (R4).
In general, it is a poor idea to try to reorient the molecule. Certain sections
of the program, such as the orbital symmetry assignment, do not know how to deal
with cases where the 'master frame' has been changed.
Linear molecules (C4v or D4h oder C2v oder D2v) must lie along the z axis, so do not try to
reorient linear molecules.
Diese Aussage stimmt nicht für COORD=UNIQUE! Man muss lineare
Moleküle entlang der y-Achse (oder x-Achse) anordnen. Mit COORD=UNIQUE braucht
(muss!) man dann auch nur
die Hälfte der Koordinaten anzugeben (s.
lineares H4).
Bei einer Anordnung entlang der z-Achse (=Drehachse) wäre obige Symmetrieangabe
auch nicht verständlich und das Programm benutzt dann auch die y-Achse als
Drehachse, was zu einer unsinnigen Geometrie führt.
You can use EXETYP=CHECK to quickly find what atoms are generated, and in what
order.
This is typically necessary in order to use the general $ZMAT coordinates.
Depending on your choice for COORD in $CONTROL,
if COORD=UNIQUE, follow card sequence U
if COORD=HINT, follow card sequence U
if COORD=CART, follow card sequence C
if COORD=ZMT, follow card sequence G
if COORD=ZMTMPC, follow card sequence M
Card sequence U is the only one which allows you to define a completely general
basis here in $DATA.
Recall that UNIT in $CONTRL determines the distance units.
-5U- Atom
input. Only the symmetry unique
atoms are input, GAMESS will generate the symmetry equivalent atoms according to
the point group selected above.
if COORD=UNIQUE
NAME, ZNUC,
X, Y, Z
NAME = 10 character
atomic name, used only for printout. Thus you can enter H or Hydrogen, or
whatever.
ZNUC = nuclear
charge. It is the nuclear charge which actually defines the atom's identity.
X,Y,Z = Cartesian
coordinates.
if COORD=HINT
NAME,ZNUC,CONX,R,ALPHA,BETA,SIGN,POINT1,POINT2,POINT3
NAME = 10 character atomic name (used only for print out).
ZNUC = nuclear charge.
CONX = connection type, choose from
'LC' linear conn. 'CCPA' central conn.
'PCC' planar central conn. with polar atom
'NPCC' non-planar central conn. 'TCT' terminal conn.
'PTC' planar terminal conn. with torsion
R = connection distance.
ALPHA= first connection angle
BETA = second connection angle
SIGN = connection sign, '+' or '-'
POINT1, POINT2, POINT3 = connection points, a serial number of a
previously input atom, or one of 4
standard points: O,I,J,K (origin and unit points on axes of master frame).
defaults: POINT1='O', POINT2='I', POINT3='J' ref- R.L. Hilderbrandt, J.Chem.Phys.
51, 1654 (1969).
You cannot understand HINT input without reading this.
Auch das nützt nicht viel!
Note that if ZNUC is negative, the internally stored basis for ABS(ZNUC) is
placed on this center, but the calculation uses ZNUC=0 after this. This is
useful for basis set superposition error (BSSE) calculations.
* * * If you gave $BASIS, continue entering cards -5U- until all the unique
atoms have been specified. When you are done, enter a " $END " card.
* * * If you did not, enter cards -6U-, -7U-, -8U-. Das
bedeutet externer Basissatz.
-6U- GBASIS, NGAUSS, (SCALF(i),i=1,4)
GBASIS has exactly the same meaning as in $BASIS. You may choose from MINI,
MIDI, STO, N21, N31, N311, DZV, DH, BC, TZV, MC, SBKJC, or HW. In addition, you
may choose S, P, D, F, G, or L to enter an explicit basis set. Here, L means an
s and p shell with a common exponent.
NGAUSS is the number of Gaussians (N) in the Pople style basis, or user input
general basis. It has meaning only for GBASIS=STO, N21, N31, or N311, and
S,P,D,F,G, or L.
Up to four scale factors may be entered. If omitted, standard values are used.
They are not documented as every GBASIS treats these differently. Read the
source code if you need to know more. They are seldom given.
* * * If GBASIS is not S,P,D,F,G, or L, either add more shells by repeating card
-6U-, or go on to -8U-.
* * * If GBASIS=S,P,D,F,G, or L, enter NGAUSS cards -7U-.
-7U- IG, ZETA, C1, C2
IG = a counter, IG takes values 1, 2, ..., NGAUSS.
ZETA = Gaussian exponent of the IG'th primitive.
C1 = Contraction coefficient for S,P,D,F,G shells, and for the s function of L
shells.
C2 = Contraction coefficient for the p in L shells.
* * * For more shells on this atom, go back to card -6U-.
* * * If there are no more shells, go on to card -8U-.
-8U- A blank card ends the basis set for this atom.
Continue entering atoms with -5U- through -8U- until all are given, then
terminate the group with a " $END " card.
--- this is the end of card sequence U ---
COORD=CART input:
-5C- Atom input.
Cartesian coordinates for all atoms must be entered. They may be arbitrarily
rotated or translated, but must possess the actual point group symmetry. GAMESS
will reorient the molecule into the 'master frame', and determine which atoms
are the unique ones.
Thus, the final order of the atoms may be different from what you enter here.
NAME, ZNUC, X, Y, Z
NAME = 10 character atomic name, used only for printout. Thus you can enter H or
Hydrogen, or whatever.
ZNUC = nuclear charge. It is the nuclear charge which actually defines the
atom's identity.
X,Y,Z = Cartesian coordinates.
Continue entering atoms with card -5C- until all are given, and then terminate
the group with a " $END " card.
--- this is the end of card sequence C ---
COORD=ZMT input: (GAUSSIAN style internals)
-5G- ATOM
Only the name of the first atom is required.
See -8G- for a description of this information.
-6G- ATOM i1 BLENGTH
Only a name and a bond distance is required for atom 2.
See -8G- for a description of this information.
-7G- ATOM i1 BLENGTH i2 ALPHA
Only a name, distance, and angle are required for atom 3.
See -8G- for a description of this information.
-8G- ATOM i1 BLENGTH i2 ALPHA i3 BETA i4
ATOM is the chemical symbol of this atom. It can be followed by numbers, if
desired, for example Si3. The chemical symbol implies the nuclear charge.
i1 defines the connectivity of the following bond.
BLENGTH is the bond length "this atom-atom i1".
i2 defines the connectivity of the following angle.
ALPHA is the angle "this atom-atom i1-atom i2".
i3 defines the connectivity of the following angle.
BETA is either the dihedral angle "this atom-atom i1- atom i2-atom i3", or
perhaps a second bond angle "this atom-atom i1-atom i3".
i4 defines the nature of BETA, If BETA is a dihedral angle, i4=0 (default). If
BETA is a second bond angle, i4=+/-1. (sign specifies one of two possible
directions).
• Repeat -8G- for atoms 4, 5, ...
• The use of ghost
atoms
is
possible,
by
using
X or
BQ for
the
chemical
symbol. Ghost atoms
preclude the option of an automatic generation of $ZMAT.
• The connectivity i1, i2, i3 may be given as integers, 1, 2, 3, 4, 5,... or as
strings which match one of the ATOMs. In this case, numbers must be added to the
ATOM strings to ensure uniqueness!
• In -6G- to -8G-, symbolic strings may be given in place of numeric values for
BLENGTH, ALPHA, and BETA. The same string may be repeated, which is handy in
enforcing symmetry. If the string is preceded by a minus sign, the numeric value
which will be used is the opposite, of course. Any mixture of numeric data and
symbols may be
given. If any strings were given in -6G- to -8G-, you must provide cards -9G-
and -10G-, otherwise you may terminate the group now with a " $END " card.
-9G- A blank line terminates the Z-matrix section.
-10G- STRING VALUE
STRING is a symbolic string used in the Z-matrix.
VALUE is the numeric value to substitute for that string.
Continue entering -10G- until all STRINGs are defined. Note that any blank card
encountered while reading -10G- will be ignored. GAMESS regards all STRINGs as
variables (constraints are sometimes applied in $STATPT). It is not necessary to
place constraints to preserve point group symmetry, as GAMESS will never lower
the
symmetry from that given at -2-. When you have given all STRINGs a VALUE,
terminate the group with a " $END " card.
--- this is the end of card sequence G ---
The documentation for sequence G above and sequence M below presumes you are
reasonably familiar with the input to GAUSSIAN or MOPAC. It is probably too
terse to be understood very well if you are unfamiliar with these. A good
tutorial on both styles of Z-matrix input can be found in Tim Clark's book "A
Handbook of Computational Chemistry", published by John Wiley & Sons, 1985.
Both Z-matrix input styles must generate a molecule which possesses the symmetry
you requested at -2-. If not, your job will be terminated automatically.
COORD=ZMTMPC input: (MOPAC style internals)
-5 M - ATOM
Only the name of the first atom is required.
See -8M- for a description of this information.
-6 M - ATOM BLENGTH
Only a name and a bond distance is required for atom 2.
See -8M- for a description of this information.
-7 M - ATOM BLENGTH j1 ALPHA j2
Only a bond distance from atom 2, and an angle with respect to atom 1 is
required for atom 3. If you prefer to hook atom 3 to atom 1, you must give
connectivity as in -8M-.
See -8M- for a description of this information.
-8 M - ATOM BLENGTH j1 ALPHA j2 BETA j3 i1 i2 i3
ATOM, BLENGTH, ALPHA, BETA, i1, i2 and i3 are as described at -8G-. However,
BLENGTH, ALPHA, and BETA must be given as numerical values only. In addition,
BETA is always a dihedral angle. i1, i2, i3 must be integers only.
The j1, j2 and j3 integers, used in MOPAC to signal optimization of parameters,
must be supplied but are ignored here. You may give them as 0, for example.
Continue entering atoms 3, 4, 5, ... with -8M- cards until all are given, and
then terminate the group by giving a " $END " card.
--- this is the end of card sequence M ---
This is the end of $DATA!
If you have any doubt about what molecule and basis set you are defining, or
what order the atoms will be generated in, simply execute an EXETYP=CHECK job to
find out!