Firefly and PC GAMESS-related discussion club


 
Learn how to ask questions correctly  
 
 
We are NATO-free zone
 



Re^4: HOMO-LUMO GAP CALCULATION DOUBT....

Siddheshwar Chopra
sidhusai@gmail.com


Dear Thomas,
Thank you so much... Didn't know that at all  :-)

Regards,


On Mon Apr 22 '13 2:45pm, Thomas wrote
--------------------------------------
>Dear Siddheshwar,

>The "-" isn't a minus sign, it's a hyphen. It's just a language thing, I guess you could also choose to write HOMO/LUMO.
>
>
>Kind regards,
>Thom
>
>
>
>
>On Sun Apr 21 '13 9:53pm, Siddheshwar Chopra wrote
>--------------------------------------------------
>>Dear Thomas,
>>Thank you for the answer.. Yes i must do lumo-homo.. But thomas why do we write homo-lumo always????

>>Regards,
>>
>>
>>Dear Thomas,
>>n Sun Apr 21 '13 3:01pm, Thomas wrote
>>--------------------------------------
>>>Dear Siddheshwar,

>>>I'm not sure if I understand your question correctly. However, I would like to propose that you should calculate the HOMO-LUMO gap with:

>>>Gap = LUMO - HOMO = 2.2 eV

>>>which gives a positive number that looks normal to me.
>>>
>>>
>>>Kind regards,
>>>Thom
>>>
>>>
>>>
>>>On Sat Apr 20 '13 9:34pm, Siddheshwar Chopra wrote
>>>--------------------------------------------------
>>>>Dear Sir,
>>>>As learnt from the same forum about calculating HOMO-LUMO, I have got the final result as follows:

>>>>Orbital No.     (in eV)
>>>>161     LUMO     -2.25     A
>>>>160     HOMO     -4.45     A

>>>>Hence the GAP= HOMO-LUMO = -2.2 eV

>>>>Now the doubt is that when I plotted the Density of states spectrum, I get to see a gap between the occupied and virtual orbitals (I have attached an image of it for your reference).. Please help me understanding this concept... Just now the calculations have shown a negative value, which in my opinion means overlapping occupied and virtual orbitals. Then how can a gap be seen? Am I going wrong in the calculations or something else. Please help..

>>>>Regards,


[ Previous ] [ Next ] [ Index ]           Mon Apr 22 '13 4:28pm
[ Reply ] [ Edit ] [ Delete ]           This message read 847 times