Subject: RMS deviation in El.stat. pot. (GAMESS)

From: Patrick Bultinck <[email-masked]>
Date: Thu, 1 Dec 1994 09:54:04 +0100 (MET)

Dear netters,

I have a question on some GAMESS (maybe other programs too) output 
generated in the fit of charges to the electrostatic potential.
The output is given underneath. It describes a fit of charges on the 
atoms in an ethylenediamine conformer. As constraints we've used :
1- the sum of charges must equal the total charge (zero)
2- fit must reproduce dipole moment
3- fit must reproduce the quadrupole moment

The algorithm used is the connolly algorithm.

Can somebody tell me what the RMS deviation (in units kcal/mole) means, 
and how do they calculate it ? On what scale do I have to view the values ?

OUTPUT

          -----------------------
          ELECTROSTATIC POTENTIAL
          -----------------------

     NUMBER OF POINTS SELECTED FOR FITTING =  1418

 NET CHARGES:
 ---------------------------
 ATOM                CHARGE
 ---------------------------
 C1                  1.7740
 C2                  1.7740
 N1                 -1.2473
 N2                 -1.2473
 H1                  0.2977
 H2                  0.2977
 H3                  0.2977
 H4                  0.2977
 H5                 -0.5611
 H6                 -0.5611
 H7                 -0.5611
 H8                 -0.5611
 ---------------------------

******Here it is******
 RMS DEVIATION IS            3.390 KCAL/MOLE
 RELATIVE RMS DEVIATION IS  38.589 %
***********************

 MULTIPOLE MOMENTS:
 ---------------------------------------------------------
 STATUS  ACTUAL VALUE       QUANTITY        FITTED VALUE 
 ---------------------------------------------------------
 FIXED       0.0000       TOTAL CHARGE       0.0000
             0.0000 D    DIPOLE MOMENT       0.0000 D
 FIXED       0.0000 D          DX            0.0000 D
 FIXED       0.0000 D          DY            0.0000 D
 FIXED       0.0000 D          DZ            0.0000 D
 FREE       -9.7610 BU         QXX          -9.7610 BU
 FIXED       2.3702 BU         QYY           2.3702 BU
 FIXED       7.3908 BU         QZZ           7.3908 BU
 FIXED     -10.5572 BU         QXY         -10.5572 BU
 FIXED       0.0000 BU         QXZ           0.0000 BU
 FIXED       0.0000 BU         QYZ           0.0000 BU
 ---------------------------------------------------------