Multiwfn forum

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?

Dear all,

I am trying to do TDDFT calculations to predict UV-Vis spectra of my compounds. I succeeded for an organic compound, but for an organometallic complex (palladium), the calculation ended with an error.

My input is as below:

%nprocshared=2
%mem=16GB
%chk=xxx.chk
#p   scf=(maxcycle=300)   pop=(nbo,full)   scrf=(smd, solvent=dichloroethane)
M06/gen   TD(NStates=30)   guess=read   nosym   int=ultrafine

filename

charge/spin
coordinates

P C H F B 0
6-311+G**
****
Pd 0
SDD
****

The error message is as below:
Excessive mixing of frozen core and valence orbitals.
Error termination via Lnk1e in xxx/g09/g09/l801.exe

I normally put pseudo=read into my inputs, but here I didn't do it because I read somewhere that this is not compatible with TDDFT. The only difference from the input for the purely organic compound is that I used a mixed basis set. I tried M06/6-311+G**/SDD with no separate basis set block, but that also ended with another error.