# Tag Info

1

I didn't deal with perovskite before, but I got this problem when I used metal atom in my complex. So, from my point of view, I think your calculation needs more cycles to get converged so what about increasing the number of cycles using keyword SCF(MaxCycle=1000) and if it didn't work well, you can use keyword SCF=XQC. XQC means you will use quadratically ...

7

Your reference paper says that it subtracts the "absolute potential of the reference electrode" from the calculated values. I can't get to the citation that explains what reference electrode they are referring to, but the most common is the Standard hydrogen electrode, which is estimated to have an absolute potential of $\pu{4.44V}$. Subtracting ...

0

I don't see the value you quote in your question anywhere in the tutorial. In any event, Gibb's Free energies in Gaussian will always be reported in Hartree, while the redox potential (which you would need to calculate using these Gibb's Free energies) is typically given in Volts. To show how this works, I'll explicitly convert their example from the last ...

5

In the dataset files for a given molecule, the charge and number of unpaired electrons for each species are stored in files .CHG1/.CHG2 and .UHF1/.UHF2 respectively. On some computers, files starting with . are hidden by default. On Mac, you can display these in Finder by pressing <COMMAND><SHIFT>.. Looking at these for molecule 45 of the OROP ...

1

Check DFTB+ with its xtb implementation. Among DFT codes working with ASE, take a look on GPAW, where you also have an external field option.

8

tldr: For a UV/Vis spectra, it shouldn't matter much. I've found that Gaussian's AM1 / PM3 implementation often breaks symmetry during optimization. So I'm not surprised at your finding. Moreover, in many cases, it's good to start with the expected symmetry geometry. For example, if I open the output in Avogadro, I can use Properties => Symmetry => ...

2

The difference between cartesian and spherical basis functions is that the latter use real spherical harmonics; for instance, $Y_{20} \propto \frac {-x^2 -y^2 +2z^2} {r^2}$. Quantum chemistry codes evaluate the basis functions or their integrals in the cartesian basis, and then use the connection between the cartesian functions and spherical functions to ...

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