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Re^2: Getting wrong result for TiO2 HOMO-LUMO gap...

Alex Granovsky
gran@classic.chem.msu.su


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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