W10

•Calculate the first 13 excited states of Hydrogen atom by using the CIS theoretical method with appropriate basis sets then compare with the experimental values.

 

Table1. Energies of the excited states of hydrogen atoms

Unit:eV 2S 2P 3S 3P 3D MAE
d-aug-cc-pVTZ 10.2 10.2 10.2 10.2 12.2 14.2 14.2 14.2 14.7 14.7 14.7 14.7 14.7 1.51
d-aug-cc-pVQZ 10.2 10.2 10.2 10.2 12.1 13.5 13.5 13.5 13.8 13.8 13.8 13.8 13.8 0.97
d-aug-cc-pV5Z 10.2 10.2 10.2 10.2 12.1 13.1 13.1 13.1 13.3 13.3 13.3 13.3 13.3 0.68
d-aug-cc-pV5Z(+difu) 10.2 10.2 10.2 10.2 12.1 12.1 12.1 12.1 12.2 12.2 12.2 12.2 12.2 0.04
Experimental values 10.2 10.2 10.2 10.2 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1

Reference : J Mol Model . 2022 Aug 30;28(9):282.

10.1

  • Conclusion : The greater utilization of function, the higher level of accuracy achieved, and add diffuse functions can yield more accurate values.

 

 

 

•Calculate the first 5 excited states of Helium by using the CIS、CIS(D) theoretical method with appropriate basis sets then compare with the experimental values.

Table2. First 5 excited states of Helium energy

CIS           (unit:eV) 1 2 3 4 5
d-aug-cc-pVTZ 21.1 22.1 22.1 22.1 24.2
d-aug-cc-pVQZ 21.1 21.9 21.9 21.9 24.0
d-aug-cc-pV5Z 21.1 21.8 21.8 21.8 23.9
d-aug-cc-pV5Z(+difu) 19.9 20.3 20.3 20.3 20.9
Experimental values 19.8 20.6

 

CIS(D)     (unit:eV) 1 2 3 4 5
d-aug-cc-pVTZ 21.1 22.1 22.1 22.1 24.2
d-aug-cc-pVQZ 21.1 21.9 21.9 21.9 24.0
d-aug-cc-pV5Z 21.1 21.9 21.9 21.9 24.0
d-aug-cc-pV5Z(+difu) 19.8 20.2 20.2 20.2 20.8
Experimental values 19.8 20.6

Reference : J Mol Model . 2022 Aug 30;28(9):282.

MAE(unit:eV) CIS CIS(D)
d-aug-cc-pVTZ 2.4 2.3
d-aug-cc-pVQZ 2.2 2.2
d-aug-cc-pV5Z 2.1 2.2
d-aug-cc-pV5Z(+difu) 0.4 0.3
  • Conclusion : Add diffuse functions can yield more accurate values.