General Format of the atomic Section of the Jaguar Input File

After the &atomic line, the atomic section should list sets of atomic input values. Each of these sets is a free-format table. The first row of the table lists the keywords whose values are to be set for each atom. This row is the column heading row. Subsequent rows list the values for the keywords for each relevant atom. For instance, in the following atomic section:

&atomic
atom  mass   vdw2
H1    2.00   1.20
H2    2.00   1.20
atom  vdw2
O     1.55
&

the keywords are atom (the atom label or number), mass (the nuclear mass in amu), and vdw2 (the van der Waals radii for PBF solvation), and the lines for the atoms H1 and H2 specify that these atoms have a nuclear mass of 2.00 amu (deuterium) and solvation van der Waals radii of 1.2 Å, while the line for atom O specifies a solvation van der Waals radius of 1.55 Å for this atom. It is not necessary to list information for atoms that are to be treated in the default manner. Keywords are case insensitive. Columns can be given in any order. All entries in a row should be separated by one or more spaces or tabs, but columns do not need to be aligned.

The atom column must be included in every set of atomic input values. The atom identifiers can be either atom labels (such as H1 or O in the example above) or atom index numbers (such as 2 for the second atom listed in the zmat input). Atom label input is case sensitive.

If you do not want to set a value for a given atom, you can use a “?” or “–” to indicate that the default value should be used. You may leave the values blank for values at the end of the row. For instance, either of the sections below has the same effect as the first atomic section example listed above.

&atomic
atom  mass   vdw2
H1    2.00   1.20
H2    2.00   1.20
O     ?      1.55
&
 
&atomic
atom  vdw2   mass
H1    1.20   2.00
H2    1.20   2.00
O     1.55
&

Atoms may be described in more than one set of atomic input values, but the same keyword cannot be used more than once for the same atom. Thus, the following syntax is supported:

&atomic 
atom basis 
C1 6-31g* 
atom formal 
C1 1 
& 

but the following syntax is not supported:

&atomic 
 atom basis 
 C1 6-31g* 
 atom basis 
 C1 cc-pVTZ 
 & 

To print an atomic section in the restart file that contains information for all atoms, not just some, set the output keyword ip29 to 2. If an atomic section exists or if ip29=2 in the input file, the atomic section is echoed in the output from the program pre.

Single Point Energy Examples

Calculation of Molecular Properties Examples

Vibrational Frequency Examples