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Re^3: HOMO-LUMO GAP CALCULATION DOUBT....

Thomas
thomaspijper@hotmail.com

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,

Mon Apr 22 '13 2:45pm