Multiwfn forum

Connolly surface is defined for molecular surface, it is not a general surface for real-space functions. You can study isosurfaces of ESP.

1 DFT-D3(BJ) doesn't directly affect result of TDDFT

2 No

3 Can be

4 Electron excitation may directly cause or induce bond-formation or bond-cleavage. You can perform geometry optimization or calculate reaction path/barrier on excited state PES to verity the anticipation.

5 No. SMD doesn't have advantage in this regard.

6 No. If you geometry essentially has symmetry, even if you use "nosymm", the calculated atomic forces are still symmetric with respect to geometry.

7 It is too cumbersome. Simply use:
(1) wB97XD/def2SVP TD(Nstates=5,Root=2) opt freq SCRF(SMD,solvent=dimethylsulfoxide)
(2) wB97XD/def2TZVP TD(Nstates=5,Root=2) SCRF(SMD,solvent=dimethylsulfoxide) guess=read geom=allcheck
Set "E=" in settings.ini of Shermo to the 2nd excited state energy obtained from step (2), then boot up Shermo and load output file of step (1), you will obtain reasonable free energy of the 2nd excited state at its minimum.

8 CAM-B3LYP frequently overestimates excitation energy of local excitations. However, if your purpose is to explore reaction path over excited states, then CAM-B3LYP doesn't have well-known flaw.

9 If TS-2 is a transition state on excited state PES, you can certainly optimize it. Note that there may be no TS between B* to C, you may need to locate minimum energy conical intersection (MECI) to study the process (if you are not familiar with it, look at materials about computational photochemistry studies)

No. They use numerical basis set, Multiwfn is impossible to support them. In addition, they are not free-of-charge, I even cannot become their user.

1 If you haven't set "nthreads" in settings.ini of Multiwfn, don't forget to set it to actual number of CPU physical cores.

2 Using better CPU will make the calculation faster.

3 Slightly increasing grid spacing (equivalent to reducing number of grids) of hole-electron analysis will reduce computational cost.

4 In the case of IFCT analysis with Hirshfeld partition, you can reduce number of atom-centered integration grids to reduce cost, the method is lowering "radpot" and "sphpot" in settings.ini before booting up Multiwfn.

5 Using IOp(9/40=3) instead of IOp(9/40=4) in Gaussian TDDFT calculation will reduce cost of hole-electron and IFCT analyses.

6 Using a smaller basis set such as 6-31G* for unimportant atoms.

Note that 3,4,5,6 will lower the accuracy.

1 Theor Chem Acc (2011) 128:295–305

2 Correct

3 Should

4 If the ion pair is not of interest, you can ignore diffuse functions; if it is important, then diffuse functions should be added to heavily negatively charged atoms in the ion pair (at least when calculating single point)

5 Yes

6 AFAIK, there is no published frequency correction factor for solvent environment, usually  it is assumed that the optimal scale factor in solvent environment does not differ notably with respect to that in gas phase.

7 Correct. But it is noted that most wavefunction analysis methods have relatively low requirement on basis set (the level for geometry optimization is already adequate for most wavefunction analyses).

1 ADCH charge more negative than -0.6 or -0.7. ADCH charge can be calculated by Multiwfn using 7-11-1.
2 It is reasonable
3 Should be
4 This fully depends on which wavefunction analysis method will be used. Only less than 30% analysis methods in Multiwfn is incompatible with diffuse functions. For example, if calculating Mayer bond order and Mulliken charge, then def2-TZVPD should no be used, unless the atoms with diffuse functions are very far from the region of interest.

For anions (more specifically, for significantly negatively charged atoms), def2-TZVP is inadequate, at least for evaluating energy and properties related to electronic structure.

Usually, a GTF with exponent less than 0.05 is regarded as a diffuse function.
Although def2-TZVP doesn't contain diffuse functtions, it is well known that it is more diffuse than 6-311G series. Note that diffuseness of 6-311G is inadequate, making its result frequently unsatisfactory (see J. Chem. Phys., 91, 7305 (1989)).

Hello,

Ehrenfest force has not been explicitly implemented in Multiwfn. But you can easily extend the source code Multiwfn to realize this aim. Stress tensor is calculated by "subroutine stress_tensor" in function.f90. Basic knowledge about modifying source code of Multiwfn can be found in http://sobereva.com/multiwfn/res/Modify … ltiwfn.pdf

Only ZPE scale factor is relatively important, you can simply set other factors to 1.

b3lyp, blyp, TPSSTPSS: Their D3 parameters are built-in in Gaussian, so do not need to customize
For BHandHLYP and TPSSh, their D3 parameters must be customized via respective IOps.

1 It should work

Hello,

Your map is not very satisfactory. I suggest you inputting the following commands in Multiwfn after loading the .xyz file

20
-10
2
279-349
c
11
279-349
4 A
0.15
3

Then use igm_inter.vmd to render the cube files, and set isovalue to 0.003 and properly modify representation, then image looks nice:

If you refer to sobEDA.sh script, there is no restart consideration. Please rerun, or manually modify the script

I have checked, at high-quality grid (corresponding to 0.13 Bohr grid spacing of your system), the 3D-spline interpolated density around some nuclei doesn't vary fully reasonably, making generation of a few bond paths unsuccessful. However, if grid spacing of 0.05 Bohr is used to generate electron density grid data, all bond paths can be successfully generated.

Unlike basin analysis in Multiwfn, the bond paths are not generated directly at grids. To generate bond paths, the derivative of electron density beyond grids must be evaluated, so it is impossible to "simply calculate the derivatives numerically on the grid"