basinfo

basinfo

This option defines the implementation details of basis functions.

angular_type

Value Cartesian. Will use Cartesian basis sets, i.e. 6d/10f/15g
spherical. Will use the spherical basis sets, i.e. 5d/7f/9g
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:

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

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.