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Re^5: Getting wrong result for TiO2 HOMO-LUMO gap...

Siddheshwar Chopra
sidhusai@gmail.com


Dear Alex,
Yes you said right..HOMO orbital is 19th. But I am getting 0.68eV using 6-31G. Could you please help me?

Kind Regards,

On Wed May 28 '14 3:49pm, Alex Granovsky wrote
----------------------------------------------
>Hello,

>with 6-31G, HOMO is orbital # 19

>Kind regards,
>Alex Granovsky
>
>
>On Wed May 28 '14 8:24am, Siddheshwar Chopra wrote
>--------------------------------------------------
>>Dear Alex,
>>A BIG Thanks for that explanation. The problem is solved..
>>But could you try with 6-31G also. I got the same problem here too. Please have a look at that.

>>Kind Regards,

>>On Tue May 27 '14 3:28pm, Alex Granovsky wrote
>>----------------------------------------------
>>>The relevant lines of output are:

>>> TOTAL NUMBER OF SHELLS              =   11
>>> TOTAL NUMBER OF BASIS FUNCTIONS     =   50
>>> NUMBER OF ELECTRONS                 =   38
>>> CHARGE OF MOLECULE                  =    0
>>> STATE MULTIPLICITY                  =    1
>>>
>>> NUMBER OF OCCUPIED ORBITALS (ALPHA) =   19
>>> NUMBER OF OCCUPIED ORBITALS (BETA ) =   19
>>>

>>> TOTAL NUMBER OF ATOMS               =    3
>>> THE NUCLEAR REPULSION ENERGY IS      124.9770929777

>>>and

>>>
>>> THE ECP RUN REMOVES   14 CORE ELECTRONS, AND THE SAME NUMBER OF PROTONS.
>>>

>>> THE ADJUSTED NUCLEAR REPULSION ENERGY=       53.0405413922

>>>So to get the HOMO # you should take 19 and then subtract 14/2  

>>>Kind regards,
>>>Alex Granovsky
>>>
>>>
>>>
>>>
>>>On Tue May 27 '14 12:34pm, Alex Granovsky wrote
>>>-----------------------------------------------
>>>>Hi,

>>>>You should take into account that ECP removes core electrons.
>>>>As a result, HOMO becomes orbital number 12, while LUMO is orbital
>>>>number 13. The HOMO-LUMO gap is then ca. 3 eV.

>>>>Kind regards,
>>>>Alex Granovsky
>>>>
>>>>
>>>>
>>>>
>>>>On Tue May 27 '14 10:16am, Siddheshwar Chopra wrote
>>>>---------------------------------------------------
>>>>>Dear Users,
>>>>>Please see the following code I am using to run for a single TiO2 molecule. I have used SBKJC and also 6-31G to get almost similar results for HOMO-LUMO gap. I am getting around 0.7 eV. However as far as literature goes, I should have got ~ 3 eV. As it a sngle TiO2 molecule, gap should have opened.

>>>>> $SYSTEM MEMORY=34459319 aoints=dist TIMLIM=5295600 KDIAG=-1 $END
>>>>> $CONTRL INTTYP=HONDO ICUT=11 ITOL=30 RUNTYP=OPTIMIZE SCFTYP=RHF $END
>>>>> $CONTRL DFTTYP=B3LYP COORD=UNIQUE NZVAR=3 $END
>>>>> $CONTRL MAXIT=10000 MOLPLT=.t. PLTORB=.t. ECP=SBKJC $END
>>>>> $BASIS GBASIS=SBKJC $END
>>>>> $STATPT opttol=10E-7 NSTEP=200 Method=GDIIS HSSEND=.TRUE. $END
>>>>> $SCF dirscf=.t. fdiff= .f. diis=.t. $END  
>>>>> $DFT HFX(1)=0.15 LMAX=41 NRAD=99 $end
>>>>> $ZMAT DLC=.t. AUTO=.t. $END
>>>>> $SCF NCONV=7 $END
>>>>> $DATA
>>>>>TiO2
>>>>>C1
>>>>> TI         22.0  -2.7439906036  -2.7281069598  -0.4118294433
>>>>> O           8.0  -3.1097257096  -4.1115914499   0.4209344416
>>>>> O           8.0  -3.1706230814  -1.3977023214   0.4765961088
>>>>> $END

>>>>>Please refer the following reference for the same:

>>>>> J. Mater. Chem. A,2014, 2,637

>>>>>Please help,

>>>>>Kind Regards,


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