General Basis Set Examples
In Spartan it is possible to use other basis sets,
and even build your own basis set.
The steps are, in brief:
Each is covered in a little more detail in the following
- create a basis file
- put this basis file in an appropriate location
- add a couple keywords to the option
line of Spartan's Calculation Dialogue
- run the job.
- Some other relevant points are raised in section 5.
- Finally, we have some links to
sample basis files.
- Create a basis file.
Examples of valid basis set files can be found
in the auxdir/basis directory (found in Spartan's install
and in the
final section of this page.
The first line should be either
the last line should be either "$end" or consist of
a series of dashes. i.e.
- BASIS="name of basis file"
The remainder of the file should be recognizable to those
who are familiar with the Gaussian basis sets.
The best way to understand this is to examine a sample file.
----- Begin Sample Basis File -----
S 2 1.0
S 2 1.0
SP 2 1.0
49.9810 0.0494720 0.511541
8.89659 0.9637820 0.612820
----- End Sample Basis File -----
Each atom section begins with a line containing the atomic symbol
and is terminated by a line of 4 asterisks
(****). The atomic symbol is followed by a set of lines
for each atomic shell. The first line of each shell consists
of 3 parts;
Each gaussian follows with the exponents and then the coefficient.
For SP shells the S coefficient comes first followed
by the P coefficient.
- the shell type, one of S,SP,D,F, or G
- the number of gaussians
- a scaling number (usually 1.0)
- Copy the basis set file to the "correct location".
This should either be your "$HOME" directory or
the .../auxdir/basis/ directory.
This file name must be in all capital letters.
- You will then need to add some keywords to your
Some useful keywords are:
|GBASIS=FILENAME.BASIS || to give the basis
set file name
|PURECART=gfd||Controls the use of either pure
or Cartesian basis function for
and d shells, respectively. 1
indicates pure and 2 Cartesian.
PURECART=112 is a common options to make
the d orbitals Cartesian, but g
and f pure.
| It is possible the default wavefunction
guess does not work well with your basis
set. One of these might work better.
|ECP=GEN ||Required if defining your own ECP.
Note: You may also have add the IGNORESYMMETRY keyword.
Symmetry often fails (with messages like "NOSasy bad") for many
- Submit the job.
Note that this is an advanced and unsupported feature. You may
get a number of errors, some due to simple mistakes in
or basis set file. Some due to numerical problems due to
our computational programs not being optimized for your basis set.
When something bad happens make sure to examine the entire
verbose output (as well as the standard terse output)
as to what went wrong. Typically the error message at
the end of
the file is misleading and you may have to page up
toward the beginning
of the file to see the first printed error.
- Other important caveats.
- Symmetry is often a problem, you may want to turn it off.
- While energies are possible with f (and g) orbitals,
charges and graphical surfaces with these high basis sets
(as well as many other electronic properties) are not
- Geometry optimization is not available for g orbitals.
- It is very easy to type in wrong values, or enter incorrectly
normalized coefficient values. This will lead to some
very strange convergence problems, or other seemingly
random error messages.
- This feature is not supported by Wavefunction. It is
supplied to expert users who are willing to debug their
- Sample Files
Here are three examples of basis set files.
- MYHOBASIS.BASIS : example
- MIXING.BASIS : showing how to
mix standard basis sets.
- ECPEX.BASIS : an example using
the ECP functionality.
- gbasis-example.spartan :
demonstrate the basis set file (MYOHBASIS.BASIS) listed in this
FAQ as well as some other advanced features.
(Clicking on this link a water molecule will
be opened with the appropriate keywords already set.)