QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: xiaoyuan on May 16, 2009, 16:15

Title: How to set the Quantum numbers when calculating the MPSH?
Post by: xiaoyuan on May 16, 2009, 16:15

Dear Doctor:
   I am very confused with the Quantum Numbers when I calculate the  MPSH. I am dealing with a system which has totally 84 valance shell electrons, and I want to calculate the MPSH of the HOMO and LUMO orbitals.(note: for the Projection Atoms, I only choose option of  the Include molecule atoms in the Analysis collum in the VNL). Some said that the quantum number of it should be 41,41 for HOMO and LUMO orbitals because each orbital contain 2 electrons, respectively. But the energy spectrum calculated like below:
-14.70
-12.89
-12.38
-11.20
-10.69
 -9.75
 -9.46
 -8.59
 -8.42
 -8.36
 -8.34
 -7.60
 -7.00
 -6.40
 -6.25
 -6.22
 -5.86
 -5.85
 -5.44
 -5.06
 -4.81
 -4.81
 -4.64
 -4.36
 -4.14
 -3.80
 -3.77
 -3.76
 -3.65
 -3.06
 -2.94
 -2.70
 -2.45
 -2.19
 -2.09
 -2.07
 -1.86
 -1.67
 -1.38
 -1.31
 -1.24
 -0.71
 -0.27
  0.77
  1.54
  2.04
According this, some one said that the 42th(-0.27) should be the HOMO and 43(0.77) should be LUMO.
So my question is :
1. when I only choose the Include molecule atoms option in vnl according which should I set the Quantum Numbers?
   according the total electrons of the valence shell or the energy spectrum?

Title: Re: How to set the Quantum numbers when calculating the MPSH?
Post by: Anders Blom on May 22, 2009, 22:40

The VNL checkboxes are really just a quick way to select certain atoms (which, anyway, doesn't work unless the structure conforms to the surface/molecule/surface model). The wavefunctions are always indexed to match the eigenvalues (the spectrum), starting at 0.