basinfo

This option defines the implementation details of basis functions.

angular_type

Value

Cartesian. Will use Cartesian basis sets, i.e. \(6d/10f/15g\cdots\)

spherical. Will use the spherical basis sets, i.e. \(5d/7f/9g\cdots\)

Default

spherical

Decide whether to use spherical or Cartesian GTO basis set. Usually, there is no need to use Cartesian GTO basis sets except for test purpose.

linear_dependence

Value

A real number

Default

1.E-8

Assign the threshold that admits the linear dependence of the basis set. It should be a positive real number. When linear dependence is detected, Qbics will stop the calculation.

ghost

Value

Atom range

Default

None

Assign “ghost atoms”, which means that those atoms defined in mol ... end have basis functions, but nuclear and electrons disappear.

This is often used for some special purposes, like basis set superposition error (BSSE) calculations, although Qbics can automatically do this.

For example, the following input:

 1basis
 2  def2-SVP
 3end
 4basinfo
 5  ghost 1-3 6 9-11 # Set ghost atoms.
 6end
 7mol # Due to the use of ghost, there are actually only 13-7=6 real atoms.
 8  C                 -1.72885348   -0.27751594   -0.54883607
 9  C                 -0.54335149   -0.47251267    0.35111257
10  C                 -1.54903120    0.59933911    0.65616163
11  H                 -1.57461433    0.15313436   -1.55374643
12  H                 -2.53379418   -1.03326873   -0.54728357
13  H                 -0.50081907   -1.36760843    0.99612354
14  H                 -2.22562112    0.47045579    1.51913545
15  H                 -1.26635100    1.65697053    0.51257787
16  C                  0.85387745   -0.06614383   -0.15308545
17  O                  1.09143365    0.21649289   -1.34006650
18  N                  1.82735682   -0.03716326    0.80612988
19  H                  2.75631019    0.21299272    0.57405353
20  H                  1.62607490   -0.26347660    1.74464638
21end

The ghost keyword indicates that in the following calculations, there will be basis functions for atom 1,2,3,6,9,10,11, but the atoms, i.e., the nuclei and electrons, are not present, disappeared like ghosts.