From: mei@vega.rc.m-kasei.co.jp (Murakami Akinori)
Newsgroups: fj.sci.chem
Subject: Dipole moment of MOPAC6
Date: 19 Aug 92 07:38:23 GMT
Distribution: fj
Organization: Mitsubishi Kasei Research Center, Yokohama, Japan

$@0J2<$O!"(JOhio Supercomputer Center$@$N7W;;2=3X%a!<%j%s%0%j%9%H$K:\$C$F$$(J
$@$?#M#O#P#A#C$NCx<T(JJ. Stewart$@$K$h$kAP6K;R%b!<%a%s(J$@%H$N<B83CM$H7W;;CM$NHf(J
$@3S$G$9!#(J

$@J,;R50F;7W;;$K4X?4$,$"$kJ}$O;29M$K$7$F$/$@$5$$!#(J

$@@5<0$JO@J8!J!)!K$K(J$@0zMQ$OFq$7$$$G$7$g$&$,!"$9$k$H$9$l$P(J
Private$@!!(Jcommunication$@$+$J!)(J

							$@B<>e!w;0I)2=@.(J


Date: Mon, 17 Aug 92 10:45:16-1795
From: Dr. James Stewart <jstewart@fai.fai.com>
Message-Id: <9208171745.AA22075@fai.fai.com>
To: chemistry@osc.edu
Precedence: bulk
Errors-To: owner-chemistry@u-tokyo.ac.jp

   DIPOLES IN SEMIEMPIRICAL METHODS

As far as I know, there have not been any comprehensive
surveys of how well semiempirical methods reproduce dipole
moments.  However, the following data might prove useful:
                                         DIPOLE MOMENTS               

   Type of Compound                           ERROR

                          PM3                   MNDO                  AM1
                    Unsigned signed       Unsigned Signed       Unsigned Signed
      HN          1   0.080   0.080         0.280   0.280         0.380   0.380
      HO          1   0.110  -0.110         0.070  -0.070         0.010   0.010
      CH         10   0.147  -0.073         0.240  -0.178         0.150  -0.066
      CO          1   0.080   0.080         0.090   0.090         0.050  -0.050
      CHO        19   0.213  -0.144         0.226  -0.151         0.149  -0.027
      CHN        17   0.390  -0.106         0.498  -0.401         0.430  -0.266
      CHNO        2   0.515  -0.515     1   0.670  -0.670     1   0.270  -0.270
      CS          1   0.740   0.740         0.230  -0.230         1.560   1.560
      CHS         6   0.432   0.432         0.070   0.027         0.193   0.130
      CSO         1   0.330  -0.330         0.320  -0.320         0.030  -0.030
      CHSO        1   0.520   0.520         0.680   0.680         0.000   0.000
      CHNS        1   0.610  -0.610         1.020  -1.020         1.360  -1.360
      CHF        11   0.210  -0.017         0.410   0.375         0.185   0.063
      CHOF        2   0.385   0.055         0.280   0.280         0.480   0.070
      CNF         2   0.740  -0.740         1.090  -1.090         1.095  -1.095
      COF         2   0.085   0.035         0.210  -0.210         0.180   0.180
      CHCl        1   0.300  -0.300         0.340   0.340         0.170  -0.170
      CHBr        8   0.223  -0.148         0.258  -0.150         0.290  -0.148
      CHOBr       1   0.520   0.520         0.020   0.020         0.160   0.160
      CFBr        2   0.185   0.065         0.350   0.350         0.215   0.155
      CHI         5   0.374  -0.374     0   0.000   0.000     0   0.000   0.000
      CFI         1   0.210  -0.210     0   0.000   0.000     0   0.000   0.000
      CBeH        1   0.240  -0.240     1   0.070  -0.070     0   0.000   0.000
      CHSi        4   0.323  -0.323         0.438  -0.438         0.245  -0.245
      CHSiS       1   0.610   0.610         1.090   1.090         0.660   0.660
      CHSiN       1   0.200  -0.200         0.200  -0.200         0.010   0.010
      CGeH        4   0.335  -0.105         0.613  -0.207         0.473  -0.348
      CGeHO       3   0.250   0.097         0.577  -0.577         0.450  -0.183
      CGeHN       1   0.300  -0.300         1.800  -1.800         0.860  -0.860
      CGeHF       1   0.950  -0.950         0.680  -0.680         0.820  -0.820
      CGeHCl      3   0.083   0.083         0.763   0.763         0.213  -0.213
      CGeHBr      2   1.020   1.020         1.135   1.135         0.275   0.005
      CSnH        3   0.183  -0.183         0.227  -0.227         0.367  -0.367
      CSnHCl      2   0.480   0.040         0.260  -0.220         0.595  -0.595
      CSnHBr      1   1.690   1.690         0.300  -0.300         0.440  -0.440
      CSnHI       1   1.290   1.290     0   0.000   0.000     0   0.000   0.000
      CPbHCl      1   0.030   0.030     0   0.000   0.000     0   0.000   0.000
      CHP         3   0.080  -0.040         0.610   0.610         0.603   0.603
      CHPF        1   0.060  -0.060         0.740   0.740         0.060  -0.060
      CAsH        1   0.390  -0.390     0   0.000   0.000     0   0.000   0.000
      CAsHCl      2   0.330   0.330     0   0.000   0.000     0   0.000   0.000
      CZnH        4   0.150  -0.050         0.220   0.025         0.180  -0.020
      CHgHN       1   0.620  -0.620     0   0.000   0.000     0   0.000   0.000
      CHgHCl      2   0.155   0.045     0   0.000   0.000     0   0.000   0.000
      CHgHBr      2   0.445   0.445     0   0.000   0.000     0   0.000   0.000
      CHgHI       2   0.845   0.605     0   0.000   0.000     0   0.000   0.000
      CSeH        3   0.627   0.627     0   0.000   0.000     0   0.000   0.000
      CSeS        1   1.260   1.260     0   0.000   0.000     0   0.000   0.000
      O           1   1.180   1.180         0.650   0.650         0.670   0.670
      HNO         3   0.177   0.077         0.390   0.390         0.290   0.290
      NO          1   0.090   0.090         0.590   0.590         0.470   0.470
      HS          1   0.800   0.800         0.510   0.510         0.890   0.890
      SO          1   2.060   2.060         2.150   2.150         2.720   2.720
      HF          1   0.430  -0.430         0.160   0.160         0.090  -0.090
      HOF         1   0.550  -0.550         0.420  -0.420         0.630  -0.630
      NOF         2   0.985  -0.565         0.745  -0.555         0.890  -0.540
      OF          1   0.080   0.080         0.020   0.020         0.190  -0.190
      NF          2   0.245   0.245         0.090  -0.090         0.350   0.150
      HCl         1   0.260   0.260         0.360   0.360         0.260   0.260
      OCl         1   2.440   2.440         0.090   0.090         0.640   0.640
      FCl         1   0.540   0.540         0.590   0.590         0.030   0.030
      SCl         1   0.230   0.230         0.620   0.620         0.330  -0.330
      HBr         1   0.430   0.430         0.230   0.230         0.550   0.550
      OBr         1   1.710   1.710         0.380   0.380         0.750   0.750
      FBr         1   0.830   0.830         0.680   0.680         0.040   0.040
      ClBr        1   0.460  -0.460         0.230   0.230         0.070  -0.070
      HI          1   0.530   0.530     0   0.000   0.000     0   0.000   0.000
      BrI         1   0.200  -0.200     0   0.000   0.000     0   0.000   0.000
      AlF         1   1.760   1.760         1.220  -1.220         0.530  -0.530
      GaF         1   1.350   1.350     0   0.000   0.000     0   0.000   0.000
      InF         1   1.320  -1.320     0   0.000   0.000     0   0.000   0.000
      InCl        1   0.120   0.120     0   0.000   0.000     0   0.000   0.000
      TlCl        1   0.330   0.330     0   0.000   0.000     0   0.000   0.000
      TlBr        1   0.410   0.410     0   0.000   0.000     0   0.000   0.000
      TlI         1   0.300   0.300     0   0.000   0.000     0   0.000   0.000
      HSiF        2   0.190   0.060         1.110   1.110         0.160   0.160
      HSiCl       2   1.520   1.520         2.075   2.075         0.570   0.570
      HSiBr       1   1.660   1.660         1.900   1.900         0.380   0.380
      GeO         1   0.210  -0.210         0.240   0.240         0.660  -0.660
      GeHN        1   0.030  -0.030         0.740  -0.740         0.710  -0.710
      GeS         1   1.520  -1.520         3.480   3.480         2.250   2.250
      GeHF        1   0.320  -0.320         0.720  -0.720         0.400  -0.400
      GeF         1   0.900  -0.900         1.970   1.970         0.540   0.540
      GeHCl       1   0.190   0.190         1.490   1.490         0.380   0.380
      GeHBr       1   1.220   1.220         1.940   1.940         0.610   0.610
      GeHI        1   0.780   0.780     0   0.000   0.000     0   0.000   0.000
      SnO         1   1.380  -1.380         1.370  -1.370         0.040   0.040
      SnS         1   0.430  -0.430         0.090  -0.090         2.540   2.540
      PbO         1   0.870  -0.870     0   0.000   0.000     0   0.000   0.000
      PbS         1   0.650  -0.650     0   0.000   0.000     0   0.000   0.000
      HP          2   0.935   0.935         0.845  -0.075         1.295   0.415
      PF          1   1.220   1.220         1.410   1.410         0.630   0.630
      POF         1   0.270   0.270         0.560  -0.560         0.880   0.880
      AsH         1   0.540   0.540     0   0.000   0.000     0   0.000   0.000
      AsCl        1   0.270  -0.270     0   0.000   0.000     0   0.000   0.000
      AsBr        1   0.240   0.240     0   0.000   0.000     0   0.000   0.000
      AsI         1   0.080  -0.080     0   0.000   0.000     0   0.000   0.000
      HgCl        1   1.220  -1.220     0   0.000   0.000     0   0.000   0.000
      HgBr        1   0.950  -0.950     0   0.000   0.000     0   0.000   0.000
      SbH         1   0.430   0.430     0   0.000   0.000     0   0.000   0.000
      SeH         2   0.760   0.760     0   0.000   0.000     0   0.000   0.000
      SeO         2   0.590   0.320     0   0.000   0.000     0   0.000   0.000
      SeF         1   0.250  -0.250     0   0.000   0.000     0   0.000   0.000
      SeOF        1   0.860   0.860     0   0.000   0.000     0   0.000   0.000
      GeSe        1   0.020  -0.020     0   0.000   0.000     0   0.000   0.000
      PbSe        1   0.310  -0.310     0   0.000   0.000     0   0.000   0.000
      GeTe        1   0.060   0.060     0   0.000   0.000     0   0.000   0.000
      SnTe        1   0.580   0.580     0   0.000   0.000     0   0.000   0.000
      PbTe        1   0.040  -0.040     0   0.000   0.000     0   0.000   0.000
 Totals:        217   0.442           165   0.513           164   0.393

 AVERAGES BY ELEMENT


 Element   No.        PM3         No.      MNDO           No.        AM1

    H       161  0.4 ( 0.1) [ 0.5]    134  0.5 ( 0.0) [ 0.7]    133  0.3 (-0.1) [ 0.4]
   Be         1  0.2 (-0.2) [ 0.2]      1  0.1 (-0.1) [ 0.1]
    C       145  0.3 ( 0.0) [ 0.5]    122  0.4 (-0.1) [ 0.5]    121  0.3 (-0.1) [ 0.4]
    N        35  0.4 (-0.2) [ 0.5]     33  0.6 (-0.4) [ 0.8]     33  0.5 (-0.3) [ 0.6]
    O        52  0.5 ( 0.1) [ 0.7]     47  0.4 (-0.1) [ 0.6]     47  0.3 ( 0.1) [ 0.6]
    F        42  0.5 ( 0.0) [ 0.6]     37  0.6 ( 0.2) [ 0.7]     37  0.4 ( 0.0) [ 0.5]
   Al         1  1.8 ( 1.8) [ 1.8]      1  1.2 (-1.2) [ 1.2]      1  0.5 (-0.5) [ 0.5]
   Si        11  0.7 ( 0.4) [ 0.9]     11  1.0 ( 0.7) [ 1.3]     11  0.3 ( 0.1) [ 0.4]
    P         8  0.5 ( 0.4) [ 0.7]      8  0.8 ( 0.4) [ 0.8]      8  0.7 ( 0.5) [ 0.9]
    S        18  0.7 ( 0.3) [ 0.8]     16  0.7 ( 0.4) [ 1.1]     16  0.8 ( 0.6) [ 1.2]
   Cl        23  0.5 ( 0.3) [ 0.8]     14  0.8 ( 0.7) [ 1.0]     14  0.3 ( 0.0) [ 0.4]
   Zn         4  0.2 (-0.1) [ 0.2]      4  0.2 ( 0.0) [ 0.3]      4  0.2 ( 0.0) [ 0.2]
   Ga         1  1.4 ( 1.4) [ 1.4]
   Ge        24  0.5 ( 0.0) [ 0.6]     21  1.0 ( 0.3) [ 1.3]     21  0.6 (-0.1) [ 0.7]
   As         7  0.3 ( 0.1) [ 0.3]
   Se        12  0.6 ( 0.5) [ 0.7]
   Br        26  0.6 ( 0.3) [ 0.8]     20  0.5 ( 0.3) [ 0.8]     20  0.3 ( 0.1) [ 0.4]
   In         2  0.7 (-0.6) [ 0.9]
   Sn        10  0.7 ( 0.1) [ 0.9]      8  0.4 (-0.4) [ 0.5]      8  0.7 ( 0.0) [ 1.0]
   Sb         1  0.4 ( 0.4) [ 0.4]
   Te         3  0.2 ( 0.2) [ 0.3]
    I        14  0.5 ( 0.1) [ 0.7]
   Hg         9  0.6 (-0.1) [ 0.8]
   Tl         3  0.3 ( 0.3) [ 0.3]
   Pb         5  0.4 (-0.4) [ 0.5]
 Totals:    618  0.4 ( 0.1) [ 0.6]    477  0.5 ( 0.0) [ 0.7]    474  0.4 ( 0.0) [ 0.6]

            AFTER ELIMINATING DOUBLE COUNTING

 Totals:    217  0.4 ( 0.1) [ 0.6]    165  0.5 ( 0.1) [ 0.7]    164  0.4 ( 0.0) [ 0.6]


  (signed average), [root mean square]

To read this table, the first part deals with types of molecule, thus the first
entry, NH, means `compounds of N and H only', in other words, ammonia.
The integers refer to the number of compounds in each class.  Where MNDO and
AM1 have the same number of compounds as PM3, the integer is dropped.
The only parameterization being done nowadays is by Prof Dewar's group,
now Prof Holder's group, by Prof Thiel, and by myself.  Prof Dewar  has developed
SAM1, which gives the following statistics:

                               SAM1    AM1   PM3
Hydrocarbons:  11              0.11    0.14  0.14
CHNO molecules 41              0.25    0.27  0.27
Halogen compounds  69          0.46    0.35  0.43

Results are mean unsigned error

Prof Thiel is developing MNDO-d, which is a very large improvement over PM3.

I was working on improving PM3, until hearing about Prof Thiel's work.
Work on PMx has now stopped.  

My gut feeling is that Prof Thiel's work is so good that even if I had developed
PM4, the results would still have been far inferior to those of MNDO-d.  

NONE of the semiempirical methods are good at predicting dipole moments.
No one method is much better than the others.  Users should chose a method
based on the results in the tables.

Many people have said that the charges in PM3, particularly on nitrogen, 
are questionable.  To quote a recent report: "The errors were reduced in
PM3 only at the expense of more serious problems, in particular incorrect
charge distributions."  The definition of charge is highly ambiguous, 
nevertheless the bulk of the evidence is that charges on N in PM3 should
not be trusted.

J.J.P. Stewart




---
Administrivia: This message is automatically appended by the mail exploder.
CHEMISTRY@osc.edu --- everybody; CHEMISTRY-REQUEST@osc.edu --- coordinator only
OSCPOST@osc.edu : send something from chemistry; FTP: kekule.osc.edu
---
--
$@Ej9F$O!"(Jchemistry@osc.edu (In English)
        chemisrty@u-tokyo.ac.jp ($@F|K\8l(J)
$@;22C?=$79~$_!"%"%I%l%9$NKu>C!"EPO?$O!"(Jchemistry-request@u-tokyo.ac.jp

chemistry@u-tokyo.ac.jp $@$KEj9F$7$F$b!"(Jchemistry@osc.edu $@$K$O(J forward 
$@$5$l$^$;$s!#(Jchemistry@osc.edu $@$KEj9F$9$k>l9g$OD>@\%a!<%k$rAw$C$F$/$@$5(J
$@$$!#(J
--
					..................................
					$@B<>eL@FA(J	$@$`$i$+$_$"$-$N$j(J
					mei@m-kasei.co.jp
					$@;0I)2=@.Am9g8&5f=j(J  $@7W;;2J3X8&5f=j(J
					..................................
Xref: sparky fj.sci.physics:387 fj.ai:682 fj.misc:533 fj.soc.tech:137