I N L EXP NG

where:

I: atom type index (integer)

N: principal quantum number (integer)

L: angular quantum number (integer)

EXP: exponent (double precision)

NG: number of gaussians for the and integrals (integer)

Atom type index is used to establish the correspondence between the basis functions and the centers (atoms). All records having the same value of I will define the basis set for all the atoms of the corresponding type.

Example:

For a calculation on the CO molecule with the following geometry data:

Geometry={ 3 C1, 0.000000000000E+00, 0.000000000000E+00, 0.000000000000E+00 O2, 0.000000000000E+00, 0.000000000000E+00,-0.117963799946E+01 O3, 0.000000000000E+00, 0.000000000000E+00, 0.117963799946E+01 }

Clementi and Roetti's Single Zeta basis set could be supplied in an external file like:

1 1 0 5.67263 12 1 2 0 1.60833 12 1 2 1 1.56788 12 2 1 0 7.65781 12 2 2 0 2.24588 12 2 2 1 2.22662 12

The first three records define the basis set for atoms of the first type (carbon in this example), and the following three, the basis set for atoms of the second type (oxygen).

NG is mandatory even in case of diatomics, though gaussian expansions will not be used, the value of NG being irrelevant in this case.

molpro@molpro.net 2019-06-17