Dear all,
I am new to NWCHEM. I am calculating the electronic coupling constant (VAB) for TiO2 cluster (Ti2O10H12). In fact, I am trying to reproduce the value reported in PRB 75, 195212 (2007). This is the polaron transfer from one Ti atom to the nearby Ti atom in the [001] direction. I calculated the reactant and product structures and obtained the same Ti-Ti and Ti-O distances as reported in the paper. However, my calculated VAB is way too small compare to the published value (0.01 vs 0.35 eV)and I have 2 questions regarding the calculations.
1. I find that the calculated SCF energies of reactant and product is the same but the calculated HAA and HBB energies in the ET module are very difference (~1 eV). Could anyone please tell what could make these values so much different?
2. The calculated overlap (SAB) is very small (3.74E-5 Hartree) and VAB is very sensitive to SAB. The spin density and charge difference confirm that the added electron localizes at the Ti center. Does anyone have an idea what could go wrong for my calculation?
Below is the input file.
start ET
geometry reactant
Ti 11.625093 6.975837 4.455000
Ti 11.625372 6.975558 7.420783
O 10.671750 6.026260 2.884880
O 12.578994 7.924437 2.885058
O 10.193823 8.410176 4.455000
O 13.056084 5.540801 4.455000
O 10.671750 6.026260 6.025120
O 12.578994 7.924437 6.024941
O 10.211400 8.393018 7.428979
O 13.039902 5.558657 7.429336
O 10.697139 6.052347 8.910000
O 12.552210 7.899188 8.910000
H 11.143818 6.496375 2.193820
H 9.994617 5.346756 2.924440
H 13.256126 8.603522 2.924618
H 9.752724 8.849322 3.724023
H 9.994617 5.346756 5.985559
H 13.256126 8.603522 5.985382
H 13.496624 5.101375 3.724023
H 10.019448 5.372284 8.910000
H 12.103299 7.451951 9.631175
H 13.230180 8.578692 8.910000
H 9.764721 8.837186 8.153541
H 13.485465 5.113512 8.153719
end
geometry product
Ti 11.625372 6.975558 4.459277
Ti 11.625093 6.975837 7.425059
O 10.697139 6.052347 2.970059
O 12.552210 7.899188 2.970059
O 10.211400 8.393018 4.451079
O 13.039902 5.558657 4.450902
O 10.671471 6.026260 5.854761
O 12.579273 7.924437 5.855117
O 10.193823 8.410176 7.425059
O 13.056084 5.540801 7.425059
O 10.671471 6.026260 8.995358
O 12.579273 7.924437 8.995001
H 11.146608 6.499305 2.248884
H 9.752724 8.849182 8.156035
H 10.019448 5.372284 2.970059
H 13.230180 8.578692 2.970059
H 9.764721 8.837186 3.726518
H 9.994338 5.346756 5.894321
H 13.256406 8.603662 5.894499
H 13.496624 5.101375 8.156035
H 13.485465 5.113512 3.726340
H 9.994338 5.346756 8.955620
H 12.106647 7.454601 9.686239
H 13.256406 8.603662 8.955441
end
basis "ao basis" spherical print
Ti library Ti ahlrichs_vtz
O library O 6-311g
H library H 6-311g
end
- reactants
set geometry reactant
charge -1.0
scf
doublet
uhf
vectors output reactant.mo
end
task scf energy
- products
set geometry product
charge -1.0
scf
doublet
uhf
vectors output product.mo
end
task scf energy
et
vectors reactants reactant.mo
vectors products product.mo
end
task scf et
|