From NWChem
You are viewing a single post from the thread title above

Edoapra Forum:Admin, Forum:Mod, bureaucrat, sysop


Forum Vet
Threads 9
Posts 1430


10:07:37 AM PST  Thu, Dec 10th 2015 

Quote:Acorreya Dec 10th 12:52 amWow! Thanks! it did work! I'm clueless of the magic numbers 63 and 58, though.. What should I do to make a bigger crystal? think I have a lot to learn!
I have extracted the magic number 63 and 58 after analyzing the following ouput (generated without the 6358 swap line)
HOMO = 0.047524
LUMO = 0.047524
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Warning  the HOMO and LUMO are degenerate and you are using symmetry.
This can lead to nonvariational energies and poor convergence.
Modify the initial guess, or use an openshell wavefunction, or turn
off symmetry.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Symmetry analysis of molecular orbitals  initial

Numbering of irreducible representations:
1 a1 2 a2 3 e 4 t1 5 t2
Orbital symmetries:
1 a1 2 t2 3 t2 4 t2 5 a1
6 t2 7 t2 8 t2 9 a1 10 t2
11 t2 12 t2 13 t2 14 t2 15 t2
16 t1 17 t1 18 t1 19 e 20 e
21 a1 22 t2 23 t2 24 t2 25 a1
26 t2 27 t2 28 t2 29 a1 30 t2
31 t2 32 t2 33 e 34 e 35 t2
36 t2 37 t2 38 t1 39 t1 40 t1
41 a1 42 t2 43 t2 44 t2 45 a1
46 t2 47 t2 48 t2 49 e 50 e
51 t1 52 t1 53 t1 54 t2 55 t2
56 t2 57 a1 58 t2 59 t2 60 t2
61 e 62 e 63 a1 64 e 65 e
66 t2 67 t2 68 t2
Starting SCF solution at 3.5s
Things to notice in the output:
1) The Warning line tells you that the HOMO and LUMO molecular orbitals are degenerate because of symmetry
2) Next, you need to browse through the "Orbital symmetries" analysis. You have 58 filled orbitals, therefore you need to find  among the unoccupied orbitals (i.e. the ones number 59 and higher)  an orbital that avoids the symmetry breaking (i.e. one electron being shared between HOMO and LUMO of the same symmetry). 63 is the first orbital  with symmetry a1  that fits the description



AWC's:
2.5.10 MediaWiki  Stand Alone Forum Extension
Forum theme style by: AWC