Manual:Basis:Atomic coordinates
From Diracwiki
Contents |
Atomic coordinates
Note that only the top six lines are shown in the input examples below.
Proton number
DIRAC
Water
aug-cc-pVDZ basis (note that a tight p has NOT been added)
C 2 2 X Y
8. 1
O .0000000000 0.0000000000 -.2249058930
...
The charge of this atom type. In the case of oxygen it is 8.
Number of unique atoms
DIRAC
Water
aug-cc-pVDZ basis (note that a tight p has NOT been added)
C 2 2 X Y
8. 1
O .0000000000 0.0000000000 -.2249058930
...
Number of symmetry-distinct atoms of this type, which is 1 for oxygen in water.
Nuclear exponent
DIRAC
Water
aug-cc-pVDZ basis (note that a tight p has NOT been added)
C 2 2 X Y
8. 1
O .0000000000 0.0000000000 -.2249058930
...
Gaussian exponent for the nuclear charge distribution. If blank, then the default value is used.
Atom name
DIRAC
Water
aug-cc-pVDZ basis (note that a tight p has NOT been added)
C 2 2 X Y
8. 1
O .0000000000 0.0000000000 -.2249058930
...
Is is recommended to use a different name for each atom of the same type in order to be able to identify them in the output. Usually one labels symmetry-distinct atoms of the same proton number with indexes. For example, hydrogen atoms in the water molecule (C1 symmetry):
...
1. 2
H1 1.4523499293 0.0000000000 0.8996235720
H2 -1.4523499293 0.0000000000 0.8996235720
...
Cartesian coordinates
DIRAC
Water
aug-cc-pVDZ basis (note that a tight p has NOT been added)
C 2 2 X Y
8. 1
O .0000000000 0.0000000000 -.2249058930
...
The x-, y-, and z coordinates are in Bohr.
DIRAC
Water
aug-cc-pVDZ basis (note that a tight p has NOT been added)
C 2 2 X Y
O .0000000000 0.0000000000 -.2249058930
...
If not blank (usually one places A character there) then the molecular coordinates are read in ångströms instead of Bohr.
The Cartesian coordinates may be given in free format. However, the name of the atom must still be left four places, and no coordinates must enter the four first positions.
