Multiwfn forum

Dear Prof. Lu,

I hope to get help with several questions on TDDFT calculation for electron-hole analysis.

1. For TDDFT, whether the functional is PBE0, LC-wPBE, CAM-B3LYP, or wB97XD, would you generally recommend DFT-D3(BJ)?

2. Is LC-wHPBE really superior to LC-wPBE as Gaussian advertises?

3. Can the same w-tuning procedure be applied whether the ground-state is singlet, doublet, or triplet, and whether it is neutral, anionic, or cationic?

4. Can electron excitation and a bond-formation or bond-cleavage reaction be concerted? Can it be calculated?

5. Is it more recommended (or not recommended) to do TD calculations with SMD rather than PCM?

6. For excited state optimization, can I just use nosymm keyword and skip the manual arbitrary breaking of symmetry?

7. For calculation of total Gibbs energy of an optimized excited state, please check if what I describe below seems correct:
  1) ES optimization (with GS checkpoint file available):
    wB97XD/def2-SVP   TD(Nstates=5, Root=2)   Opt   SCRF=solvent=dimethylsulfoxide   geom=modify   ...   geometry modification
  2) Take the structure and .chk file from 1). Run freq calculation:
    wB97XD/def2-SVP   TD(read, Nstates=5, Root=2)   Freq   SCRF=solvent=dimethylsulfoxide   guess=read
  3) Take the structure and .chk file from 1). Run SP calculation (gas-phase):
    wB97XD/def2-TZVP   TD(Nstates=5, Root=2)   guess=read
  4) Take the structure and .chk file from 1). Run SP calculation (gas-phase):
    M052X/6-31G*   TD(Nstates=5, Root=2)   guess=read
  5) Take the structure and .chk file from 1). Run SP calculation (solution-phase):
    M052X/6-31G*   TD(Nstates=5, Root=2)   SCRF=solvent=dimethylsulfoxide   guess=read
  6) Calculate E = E(step 3) + E(step 5) - E(step 4). Put it into Shermo and use .out file from step 2. Get thermal correction.

8. Suppose I have a reaction pathway A -> TS-1 -> B -> B* -> TS-2 -> C. The excited state B* is a charge-transfer state, for which I would want to use a long-range-corrected functional, such as CAM-B3LYP. But CAM-B3LYP would be less appropriate for calculation of other states A, B, TS-1, and TS-2. But then, for reaction coordinate energy calculations, shouldn't the functional be consistently used for every molecule from A to C?

9. For the TS-2 between B* and C in the question 8, am I looking for "excited state of transition state"? I don't know how to think about it.

Dear Prof. Lu,

I’d be really grateful if I could get additional clarifications on dealing with diffuse functions (and some additional questions on ZPE correction)

  1. If I use the complete set of ma-def2 series that you provided, how should I cite it when I publish?

  2. If the net charge of my molecule is overall -1, but each atom is not significantly negatively charged (ADCH charge > -0.5), diffuse functions are not required. Correct?

  3. In my reaction A + B -> [A-B], some atoms in the product [A-B] are significantly negatively charged, but not in the reactant forms (A and B). For the sake of reaction energy calculation, should these atoms be calculated using diffuse functions for both reactant (A and B) and product ([A-B]) calculations?

  4. A molecule is overall neutral, and there is no atom with a significant negative charge. But it is a tight ion-pair, in which the cation and anion counterparts are electrostatically bound and deform each other's structure. The binding is strong, but it is still non-covalent. Should diffuse functions be widely used?

  5. When using Shermo for a solute, the sophisticated way of input for Shermo setting is:
E = E(gas, high-level basis set) + [E(SMD, M05-2X/6-31G*) - E(gas, M05-2X/6-31G*)] + 1.89 kcal/mol.
  Am I correct?

  6. When I do opt-freq calculations using SCRF(IEFPCM), the ZPE values are, not surprisingly, different from the values from gas-phase optimization. This will be same for the molecules in F38/10 database used to obtain the scale factor. Then, shouldn't the ZPE scale factor become different?

  7. For wavefunction analysis of a solute, it is recommended to calculate with high-level basis set & SMD. But at the same time, for the calculation of the solute's solvation energy, the same structure should be calculated with M05-2X/6-31G*. Am I correct?

Dear Prof. Lu,

  I know that many functions of Multiwfn are incompatible with diffuse functions. But I’m confused with the definition of diffuse functions.
  What I attached here is the basis set information for the same atom (boron) in the same molecule, left one using 6-311+g** and right one using def2-TZVP.
  Although 6-311+g** is said to have diffuse functions (and def2-TZVP does not), the def2-TXVP setting also contains a S-type function with an exponent smaller than 0.1 (the last S-type in the right figure, exponent=0.06056). Also, the def2-TZVP setting contains an additional D-type function (exponent=0.199) that is more “diffuse” than the sole D-type function in the 6-311+g** setting (exponent=0.401).
  So, what is the exact standard for calling a basis set diffuse or not?

Dear Prof. Lu,

The Shermo code utilizes frequency scale factors for ZPE, U(T)-U(0), S, and CV. I can find the scale factors for ZPE in the literature, but the other three factors are rarely documented (especially, I could not find the factors for CV). So I'd like to ask if the following routine would work.

1. Fit the fundamental frequency factor for my functional/basis set using a database (F38/10 for example).
2. Run a opt-freq calculation for my molecule, and tabulate the computed harmonic frequencies.
3. Multiply the computed frequencies by the fitted fundamental frequency factor.
4. Put the results as the custom frequencies into a new freq calculation input with freq=(ReadFC, ReadIsotopes) keyword. (Or use scale keyword)
5. Use the output of the new freq calculation as the input file for Shermo, with the following settings:
  5-1. sclZPE, sclheat, sclS, sclCV = 1.0
  5-2. ilowfreq = 2 or 3

Dear all,

I loaded my .fch file to Multiwfn, chose option 21 / suboption 2 for Shubin Liu's EDA, then loaded my .out file (with ExtraLinks=L608 input). Then I saw the error message (I uploaded the screenshot file) then the Multiwfn immediately terminated.

What should I do?