Chapter 31. Electrostatic Potential Charges (ESP)

Table of Contents

Input File ( properties/prop_esp_sto6g.dat ):
Archive File ( properties/prop_esp_sto6g.arc ):
Ouput File ( properties/prop_esp_sto6g.out ):

Methanol using the MNDO model is computed with several ESP options on the common keyword line.

Input File ( properties/prop_esp_sto6g.dat ):

  mndo rhf singlet esp t=auto truste symavg sto6g
Methanol
ESP STO6G
 H              0.000000  0    0.000000  0    0.000000  0    0    0    0
 C              1.094000  1    0.000000  0    0.000000  0    1    0    0
 O              1.425000  1  107.000000  1    0.000000  0    2    1    0
 H              0.945000  1  108.500000  1  180.000000  1    3    2    1
 H              1.094000  1  107.000000  1  -60.000000  1    2    3    4
 H              1.094000  1  107.000000  1   60.000000  1    2    3    4
 0              0.000000  0    0.000000  0    0.000000  0    0    0    0
	

Archive File ( properties/prop_esp_sto6g.arc ):

  Timestamp:  2011-08-31-12-49-32-0000000DB0-win64
 User Info:  John Millam, Nahum, 

                     SUMMARY OF MNDO CALCULATION
                                                       Aug-31-2011
                          AMPAC Version 10.0.1
                             Presented by:
  
                        Semichem, Inc.
                        www.semichem.com
  
 FORMULA: C1H4O1
 Methanol
 ESP STO6G

     GEOMETRY OPTIMIZED : ENERGY MINIMIZED
     SCF FIELD WAS ACHIEVED
 
          FINAL HEAT OF FORMATION   =       -57.354085 kcal
                                    =      -240.026847 kJ
          ELECTRONIC ENERGY         =     -1079.569556 eV
          CORE-CORE REPULSION       =       572.058012 eV
          TOTAL ENERGY              =      -507.511543 eV
          GRADIENT NORM             =         0.105459 
          RMS GRADIENT NORM         =         0.030443 
          UNSTABLE MODE(S)          =         0 ( ESTIMATE  )
          IONIZATION POTENTIAL      =        11.415002 eV
          HOMO-LUMO GAP             =        15.204817 eV
          DIPOLE                    =         1.479060 debyes
          MOLECULAR WEIGHT          =        32.042000 
          MOLECULAR POINT GROUP     = Cs      0.100000
          NO. OF FILLED LEVELS      =         7 (OCC = 2)
          TOTAL NUMBER OF ORBITALS  =        12
          COMPUTATION TIME          =         0.20     SECONDS

          FINAL GEOMETRY OBTAINED                                       CHARGE
 MNDO RHF SINGLET ESP T=AUTO TRUSTE SYMAVG STO6G
 Methanol
 ESP STO6G
  H     0.000000  0    0.000000  0    0.000000  0      0     0     0    0.0161    1
  C     1.114964  1    0.000000  0    0.000000  0      1     0     0    0.1928
  O     1.390658  1  108.078001  1    0.000000  0      2     1     0   -0.3291
  H     0.946542  1  111.587140  1  180.000000  1      3     2     1    0.1803
  H     1.119107  1  112.312290  1  -60.585897  1      2     3     4   -0.0300
  H     1.119107  1  112.312290  1   60.585897  1      2     3     4   -0.0300
  0     0.000000  0    0.000000  0    0.000000  0      0     0     0
	

1

These are the Coulson charges from AMPAC, not the ESP values.

Ouput File ( properties/prop_esp_sto6g.out ):

  Timestamp: 2011-08-31-12-49-32-0000000DB0-win64
 User Info: John Millam, Nahum, 
 *******************************************************************************
                         MNDO CALCULATION RESULTS
 *******************************************************************************
 *                             AMPAC Version 10.0.1
 *                                Presented by:
 *
 *                           Semichem, Inc.
 *                           www.semichem.com
 *
 *  MNDO     - THE MNDO HAMILTONIAN TO BE USED
 *  RHF      - RESTRICTED HARTREE-FOCK CALCULATION
 *  TRUSTE   - MINIMIZE ENERGY USING TRUST REGION METHOD
 *  T=AUTO   - AUTOMATIC DETERMINATION OF ALLOWED TIME
 *  ESP      - ELECTROSTATIC POTENTIAL CALCULATION
 *  SYMAVG   - AVERAGE SYMMETRY EQUIVALENT ESP CHARGES
 *  STO6G    - DEORTHOGONALIZE ORBITALS IN STO-6G BASIS
 *  SINGLET  - IS THE REQUIRED SPIN MULTIPLICITY
 *******************************************************************************
 MNDO RHF SINGLET ESP T=AUTO TRUSTE SYMAVG STO6G
 Methanol
 ESP STO6G
    ATOM    CHEMICAL   BOND LENGTH    BOND ANGLE    TWIST ANGLE
   NUMBER   SYMBOL     (ANGSTROMS)     (DEGREES)     (DEGREES)
    (I)                   NA:I          NB:NA:I      NC:NB:NA:I     NA    NB    NC
      1     H 
      2     C          1.09400 *                                     1
      3     O          1.42500 *      107.00000 *                    2     1
      4     H          0.94500 *      108.50000 *   180.00000 *      3     2     1
      5     H          1.09400 *      107.00000 *   -60.00000 *      2     3     4
      6     H          1.09400 *      107.00000 *    60.00000 *      2     3     4

   MOLECULAR POINT GROUP            SYMMETRY CRITERIA
            Cs                          0.10000000

          SINGLET STATE CALCULATION

          RHF CALCULATION, NO. OF DOUBLY OCCUPIED LEVELS =       7

        **  REFERENCES TO PARAMETERS  **

 H  (MNDO):  M.J.S. DEWAR, W. THIEL, J. AM. CHEM. SOC., 99, 4899, (1977)
 C  (MNDO):  M.J.S. DEWAR, W. THIEL, J. AM. CHEM. SOC., 99, 4899, (1977)
 O  (MNDO):  M.J.S. DEWAR, W. THIEL, J. AM. CHEM. SOC., 99, 4899, (1977)
 
              -------------------------
              * External Contributors *
              -------------------------
 
 Electrostatic Potential Charge Calculation:
 -------------------------------------------
 The ESP charge method was contributed by Brent B. Besler (Wayne State
 University) and Kenneth D. Merz (Penn State University).


          CARTESIAN COORDINATES
      ATOM            X               Y               Z
       1 H        0.00000000      0.00000000      0.00000000
       2 C        1.09400000      0.00000000      0.00000000
       3 O        1.51062968      1.36273428      0.00000000
       4 H        2.45530585      1.38747149      0.00000000
       5 H        1.50072533     -0.45881778     -0.90603353
       6 H        1.50072533     -0.45881778      0.90603353

 STANDARD DEVIATION ON ENERGY   (KCAL)       0.00000055520
 STANDARD DEVIATION ON GRADIENT (KCAL/A,RD,RD)  0.00009841 0.00010918 0.00009144

 MNDO RHF SINGLET ESP T=AUTO TRUSTE SYMAVG STO6G
 Methanol
 ESP STO6G

     GEOMETRY OPTIMIZED : ENERGY MINIMIZED
     SCF FIELD WAS ACHIEVED

                              MNDO CALCULATION
                                                            VERSION 10.0.1

                                                       Aug-31-2011
 
          FINAL HEAT OF FORMATION   =       -57.354085 kcal
                                    =      -240.026847 kJ
          ELECTRONIC ENERGY         =     -1079.569556 eV
          CORE-CORE REPULSION       =       572.058012 eV
          TOTAL ENERGY              =      -507.511543 eV
          GRADIENT NORM             =         0.105459 
          RMS GRADIENT NORM         =         0.030443 
          UNSTABLE MODE(S)          =         0 ( ESTIMATE  )
          IONIZATION POTENTIAL      =        11.415002 eV
          HOMO-LUMO GAP             =        15.204817 eV
          MOLECULAR WEIGHT          =        32.042000 
          MOLECULAR POINT GROUP     = Cs      0.100000
          NO. OF FILLED LEVELS      =         7 (OCC = 2)
          TOTAL NUMBER OF ORBITALS  =        12
          SCF CALCULATIONS          =         7
          COMPUTATION TIME          =         0.19     SECONDS

    ATOM    CHEMICAL   BOND LENGTH    BOND ANGLE    TWIST ANGLE
   NUMBER   SYMBOL     (ANGSTROMS)     (DEGREES)     (DEGREES)
    (I)                   NA:I          NB:NA:I      NC:NB:NA:I     NA    NB    NC
      1     H 
      2     C          1.11496 *                                     1
      3     O          1.39066 *      108.07800 *                    2     1
      4     H          0.94654 *      111.58714 *   180.00000 *      3     2     1
      5     H          1.11911 *      112.31229 *   -60.58590 *      2     3     4
      6     H          1.11911 *      112.31229 *    60.58590 *      2     3     4

   MOLECULAR POINT GROUP            SYMMETRY CRITERIA
            Cs                          0.10000000

          RHF EIGENVALUES
    -41.93366    -27.81197    -18.66532    -15.39933    -15.31487    -12.81818
    -11.41500      3.78981      3.93566      4.69959      5.00626      6.75555

          NET ATOMIC CHARGES AND DIPOLE CONTRIBUTIONS    1
      ATOM            CHARGE        ATOM ELECTRON DENSITY
       1 H            0.0161          0.9839
       2 C            0.1928          3.8072
       3 O           -0.3291          6.3291
       4 H            0.1803          0.8197
       5 H           -0.0300          1.0300
       6 H           -0.0300          1.0300

 DIPOLE (DEBYE)   X         Y         Z       TOTAL
 POINT-CHG.     0.322    -0.732     0.000     0.800
 HYBRID         0.631    -0.399     0.000     0.746
 SUM            0.953    -1.131     0.000     1.479


          CARTESIAN COORDINATES
      ATOM            X               Y               Z
       1 H        0.00000000      0.00000000      0.00000000
       2 C        1.11496358      0.00000000      0.00000000
       3 O        1.54650069      1.32200813      0.00000000
       4 H        2.49126828      1.37994386      0.00000000
       5 H        1.46648332     -0.56168231     -0.90185805
       6 H        1.46648332     -0.56168231      0.90185805


          ATOMIC ORBITAL ELECTRON POPULATIONS
      0.98392      1.22135      0.91613      0.78148      0.88826      1.81752
      1.23477      1.31288      1.96394      0.81966      1.03004      1.03004

            ELECTROSTATIC POTENTIAL CHARGES

       CHARGE ON SYSTEM =    0.0000
      ATOM      CHARGE   SCALED CHARGE    2
       1 H      0.0284      0.0403
       2 C      0.1978      0.2813
       3 O     -0.4802     -0.6828
       4 H      0.3060      0.4352
       5 H     -0.0259     -0.0368
       6 H     -0.0262     -0.0372

            THE NUMBER OF POINTS IS:       427    3
            THE RMS DEVIATION IS:       0.9229
            THE RRMS DEVIATION IS:      0.1354

     DIPOLE MOMENT EVALUATED FROM THE POINT CHARGES

             X        Y        Z       TOTAL
           0.7879  -0.8800  -0.0012   1.1812

   ELECTROSTATIC POTENTIAL CHARGES AVERAGED FOR
   SYMMETRY EQUIVALENT ATOMS    4

      ATOM      CHARGE   SCALED CHARGE
       1 H      0.0284      0.0403
       2 C      0.1978      0.2813
       3 O     -0.4802     -0.6828
       4 H      0.3060      0.4352
       5 H     -0.0260     -0.0370
       6 H     -0.0260     -0.0370

         TIME TO CALCULATE ESP:     0.03 SECONDS    5
 
     ELAPSED WALL CLOCK TIME :      0.24 SECONDS
     FULL COMPUTATION TIME :      0.23 SECONDS
	

1

This table lists the Coulson charges predicted by AMPAC based on its analysis of the final density matrix.

2

This table presents the ESP charges. Note that since MNDO was used as the model, the charges were scaled by 1.422. This is the column labeled SCALED CHARGE.

3

This line is a count of the number of points on the Connolly surface used in this calculation.

4

As called for by the SYMAVG keyword, the charges of symmetrically related atoms are averaged to account for the asymmetry of the surface.

5

The user should be aware that an ESP calculation can be quite expensive computationally. In many cases, virtually all of the CPU time required for the entire job is spent in the ESP routines. STO3G can be used in place of STO6G for a faster (but less accurate) charges.