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Re^9: Getting wrong result for TiO2 HOMO-LUMO gap...(SOLVED)

Siddheshwar Chopra
sidhusai@gmail.com


Dear Alex,
Thanks for the help. I really forgot this during calculation. I will keep this in mind for sure.

Regards,

On Fri May 30 '14 1:08pm, Alex Granovsky wrote
----------------------------------------------
>Dear Siddheshwar,

>you should always use orbitals and orbital energies obtained at optimized geometry.

>From your output:

>E(HOMO)=-0.2316    E(LUMO)= -0.1198
>HOMO-LUMO gap = 0.1118 au = 3.04219 eV

>Kind regards,
>Alex Granovsky
>
>
>
>
>
>
>
>On Fri May 30 '14 7:33am, Siddheshwar Chopra wrote
>--------------------------------------------------
>>Dear Alex,
>>Please find attached the TiO2 o/p file for your reference. I used 1 Hartree=27.21 eV. Please let me know what wrong am I doing.

>>Kind Regards,

>>On Thu May 29 '14 3:12pm, Alex Granovsky wrote
>>----------------------------------------------
>>>Most likely, you are using wrong conversion factor from au to eV.

>>>Kind regards,
>>>Alex Granovsky
>>>
>>>
>>>
>>>On Thu May 29 '14 7:11am, Siddheshwar Chopra wrote
>>>--------------------------------------------------
>>>>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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