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

Alex Granovsky
gran@classic.chem.msu.su


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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