Multiwfn forum

Hi,

I am doing ONIOM calculations on a small protein and would like to do analyze the ONIOM output using Multiwfn. The geometry optimization works fine and converges but when I try to do a subsequent single point calculation to generate the wfn files using following header:

%mem=500MW
%chk=ONIOM_optimized.chk
#P oniom(b3lyp/3-21g:hf/sto-3g:amber) nosymm geom=check iop(2/15=3) test output=wfn

I get abnormal termination with this error at the end of the g09 logfile:  "Punch of MOs requested, but none found."

I looked it up but there is nothing on the web. I was hoping to get some advice on what I could be doing wrong?

I would greatly appreciate any comments.

Best wishes,

Maz.

Hello,

I am wondering if Multiwfn could be used to calculate Quantum mechanical polar surface area (QMPSA) as described by Schaftenaar and Vlieg here: J Comput Aided Mol Des. 2012 Mar; 26(3): 311–318 doi:  10.1007/s10822-012-9557-y

In the output of Quantitative surface analysis (function 12), "Positive surface area" and "Negative surface area" always add up to "Overall surface area". Is this because Multiwfn considers the surface to be either positive or negative?

Is there a way to define a an apolar surface criteria (e.g. upper and lower limits of the electrostatic potential to be treated as polar) in Multiwfn so that the calculated positive and negative surface area values would more representative of polar surface area?

I would appreciate any comments on this.

Maz.

Hello,

Multiwfn returns zero for "negative surface area" when performing quantitative analysis of molecular surface (12) on the wfn of 3,4,5-trifluorotoluene  and 4-nitrotoluene. The structures were optimized at b3lyp level with 6-31g(d,p) basis set.

Could anyone help me figure out what could be the problem and a possible solution to this?

Thanks very much in advance.

Here is the summary of calculation for 3,4,5-trifluorotoluene and I am using Version 3.5, release date: 2018-Apr-6 but I get the same problem trying Version 3.6(dev), release date: 2018-Aug-2.

================= Summary of surface analysis =================

Volume:   964.48414 Bohr^3  ( 142.92184 Angstrom^3)
Estimated density according to mass and volume:    1.6976 g/cm^3
Minimal value:    549.66960 kcal/mol   Maximal value:   1105.01382 kcal/mol
Overall surface area:         546.75577 Bohr^2  ( 153.10723 Angstrom^2)
Positive surface area:        546.75577 Bohr^2  ( 153.10723 Angstrom^2)
Negative surface area:          0.00000 Bohr^2  (   0.00000 Angstrom^2)
Overall average value:    1.31433044 a.u. (    824.75549 kcal/mol)
Positive average value:   1.31433044 a.u. (    824.75549 kcal/mol)
Negative average value:          NaN a.u. (          NaN kcal/mol)
Overall variance (sigma^2_tot):  0.05805716 a.u.^2 ( 22861.09768 (kcal/mol)^2)
Positive variance:        0.05805716 a.u.^2 (  22861.09768 (kcal/mol)^2)
Negative variance:        0.00000000 a.u.^2 (      0.00000 (kcal/mol)^2)
Balance of charges (miu):   0.00000000
Product of sigma^2_tot and miu:   0.00000000 a.u.^2 (    0.00000 (kcal/mol)^2)
Internal charge separation (Pi):   0.20965058 a.u. (    131.55784 kcal/mol)

Surface analysis finished!