QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: 7we on February 29, 2016, 20:45

Title: Electron Affinity/ Ionization Energy of Isolated Benzene
Post by: 7we on February 29, 2016, 20:45
I tried to calculate the EA and IA of an  isolated benzene molecule by following the manual,but unfortunately there are differences between my results and the ones in the manual.

State      Charging Energy
+2:  Manual: -15.37  Me: -9.940
+1:  Manual: -9.15     Me:-7.29
0:    Manual:  2.34    Me:0.216
-1:   Manual:  8.39    Me:2.384


Total Energies
+2:  Manual: -1014.57   Me: -1022.27
+1:  Manual: -1030.3     Me:--1032.21
0:    Manual: -1039.45   Me:-1039.5
-1:   Manual:  -1037.11    Me: -1039.28
-2:  Manual:  -1028.72  Me: -1028.72

I did not change any parameters except the charge, as it was explained in the manual but still the total energy of my calculation is different from the ones in  manual, leading to different EA and EI. I would appreciate if someone can explain this discrepancy in the results.

Thanks
Title: Re: Electron Affinity/ Ionization Energy of Isolated Benzene
Post by: Jess Wellendorff on March 1, 2016, 08:44
Exactly where in the ATK Reference Manual did you look? This info will most likely increase the number of forum members that will be able to answer to your post.
Title: Re: Electron Affinity/ Ionization Energy of Isolated Benzene
Post by: Ulrik G. Vej-Hansen on March 1, 2016, 09:13
This question is about section 2 in the tutorial "Benzene Single-Electron Transistor" http://quantumwise.com/documents/tutorials/latest/BenzeneSET/index.html/index.html

In order to get the same numbers as shown in the tutorial, you need to set the Poisson Solver to Multigrid and the boundary conditions to Multipole. I realized yesterday that this is not shown explicitly in the tutorial, and we will add it when it is next updated.
Title: Re: Electron Affinity/ Ionization Energy of Isolated Benzene
Post by: 7we on March 1, 2016, 18:04
Quote from: Ulrik G. Vej-Hansen on March  1, 2016, 09:13
This question is about section 2 in the tutorial "Benzene Single-Electron Transistor" http://quantumwise.com/documents/tutorials/latest/BenzeneSET/index.html/index.html

In order to get the same numbers as shown in the tutorial, you need to set the Poisson Solver to Multigrid and the boundary conditions to Multipole. I realized yesterday that this is not shown explicitly in the tutorial, and we will add it when it is next updated.
Thank you very much!