Description of a simple MOPAC2007 Output File

(move the cursor over the file to see what the parts are)

When a request is made for a license key, a unique site number is assigned. This can be used for identifying the site where MOPAC2007 is being used. The site number is unique to each site.
MOPAC2007 is made available at no cost for Academic use. A condition of that use is that the program should not be used in any for-profit activity. This means that if you want to use MOPAC2007 in research for a for-profit organization you will need to get a commercial license.
The version number refers to the particular compilation of MOPAC2007. The first number is the year (here 2007), the three decimals refer to the Julian date (here the 60th day of the year), and the letter indicates the platform Windows (W) or Linux (L).
The "days remaining" shows how long this version of MOPAC2007 will be valid for. Each new version of MOPAC2007 is valid for one year from its date of creation, so the "days remaining" can be re-set by downloading a new copy of MOPAC2007 from
Until PM6 is published, the only reference available is the program MOPAC2007.
The specific NDDO method used in the calculation is given here.
The precise date and time that the calculation was started is given here
Keyword "T=" can be used to define the CPU time allowed for this calculation. If the keyword is not used (this case), then the default of two days is used.
"DUMP=n" can be used to set the time between writing a restart file. If a restart file is written, and the job is stopped, then in most cases it can be restarted by using RESTART and, optionally, OLDENS. If the keyword is not used (this case), then the default of two hours is used.
At the start of a calculation, all keywords are echoed back. In this case, the only keyword used is "AM1." If there is any doubt of which keywords were used, this line should be read.
The second and third lines of the imput data set are output here. These lines are not used by the program, they are indended for documenting the calculation.
 ** Site#:  1321            For non-commercial use only         Version 7.060W **
 ** Cite this work as: MOPAC2007, James J. P. Stewart, Stewart Computational  **
 ** Chemistry, Version 7.060W web: HTTP://   Days remaining: 366 **
 **                                                                           **
 **                                MOPAC2007                                  **
 **                                                                           **

                            AM1 CALCULATION RESULTS

 *  CALCULATION DONE:                                Thu Mar  1 16:17:07 2007  *
 *  AM1      - The AM1 Hamiltonian to be used
 *  T=       - A TIME OF 172800.0 SECONDS REQUESTED
Formic acid
Example of normal geometry definition
The input geometry is output here. An atom's position is defined using internal coordinates if it has a connectivity (a number in the NA column), otherwise it is in Cartesian coordinates. The optimization flag "1" is replaced here by "*"
The original journal reference for all elements used in the calculation are printed.
The Point-Group theory point group of the starting geometry is printed. This might be different from the point-group at the end of the calculation if the geometry changes significantly.
The type of calculation (RHF, UHF, ROHF, etc.) is given here. If ROHF, then the open-shell or active space will be indicated by the fractional occupancy of the M.O.s used in the SCF calculation.
The empirical formula is printed. This is the number and type of each element used in the calculation.
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 O 0.0000000 0.000000 0.000000 2 C 1.2000000 * 0.000000 0.000000 3 O 1.3200000 * 116.800000 * 0.000000 2 1 0 4 H 0.9800000 * 123.900000 * 0.000000 3 2 1 5 H 1.1100000 * 127.300000 * 180.000000 2 1 3 CARTESIAN COORDINATES NO. ATOM X Y Z 1 O 0.0000 0.0000 0.0000 2 C 1.2000 0.0000 0.0000 3 O 1.7952 1.1782 0.0000 4 H 1.3156 2.0328 0.0000 5 H 1.8726 -0.8830 0.0000 H: (AM1): M.J.S. DEWAR ET AL, J. AM. CHEM. SOC. 107 3902-3909 (1985) C: (AM1): M.J.S. DEWAR ET AL, J. AM. CHEM. SOC. 107 3902-3909 (1985) O: (AM1): M.J.S. DEWAR ET AL, J. AM. CHEM. SOC. 107 3902-3909 (1985) Empirical Formula: C H2 O2 MOLECULAR POINT GROUP : Cs RHF CALCULATION, NO. OF DOUBLY OCCUPIED LEVELS = 9
The geometry optimization process can be followed by watching how the heat of formation and gradient norm decrease as the number of cycles of optimization increases.
Geometry optimization normally stops when the gradient norm, in kcal/mol/(Angstrom or radian), drops below 1.0.
This is the normal geometry optimization termination message. If you get this message, then most likely the calculation was successful
This is the normal Self Consistent Field calculation termination message. If any other message is printed, the calculation is most likely faulty
DIAGONAL MATRIX USED AS START HESSIAN CYCLE: 1 TIME: 0.000 TIME LEFT: 2.00D GRAD.: 118.472 HEAT:-91.15276 CYCLE: 2 TIME: 0.000 TIME LEFT: 2.00D GRAD.: 64.573 HEAT:-93.61392 CYCLE: 3 TIME: 0.016 TIME LEFT: 2.00D GRAD.: 23.477 HEAT:-95.72593 CYCLE: 4 TIME: 0.000 TIME LEFT: 2.00D GRAD.: 16.802 HEAT:-96.77744 CYCLE: 5 TIME: 0.000 TIME LEFT: 2.00D GRAD.: 14.051 HEAT:-97.31996 CYCLE: 6 TIME: 0.000 TIME LEFT: 2.00D GRAD.: 4.873 HEAT:-97.39856 CYCLE: 7 TIME: 0.000 TIME LEFT: 2.00D GRAD.: 1.076 HEAT:-97.41413 CYCLE: 8 TIME: 0.000 TIME LEFT: 2.00D GRAD.: 0.467 HEAT:-97.41479 RMS GRADIENT = 0.46676 IS LESS THAN CUTOFF = 1.00000 ------------------------------------------------------------------------------- AM1 Formic acid Example of normal geometry definition GEOMETRY OPTIMISED USING EIGENVECTOR FOLLOWING (EF). SCF FIELD WAS ACHIEVED AM1 CALCULATION MOPAC2007 (Version: 7.060W) Thu Mar 1 16:17:07 2007 No. of days left = 366
In MOPAC, the Heat of Formation is defined as the heat required in kcal/mol or KJ/mol to form one mole of a substance from its elements in their standard state at 298K. For molecules and ions, the substance is gas-phase, for solvated, solution phase, and for crystals, the solid state.
The total energy is the sum of the electronic and nuclear (core-core) energies. This quantity is only useful in debugging. It cannot be related to any observable or to anything calculated using high level methods.
The COSMO area is the total Solvent Accessible Surface area of the molecule. The default solvent is water.
The COSMO area is the size of the cavity that would need to exist in water (the default solvent) for one molecule of the substance in solution.
The Ionization potential, in eV, is the smallest energy required to remove an electron. In RHF calculations, it is the negative of the Highest Occupied Molecular Orbital energy (Koopmans' theorem), for UHF the HOMO can be of either spin up or down, and for odd-electron ROHF systems it is the negative of the Singly Occupied Molecular Orbital energy, corrected for the error arising from the use of "half electrons".
Number of doubly-occupied levels. For UHF, the number of alpha and beta electrons is given. For ROHF, the number of doubly filled and fractionally filled levels is output. In this example, there are 9 filled levels corresponding to the 18 valence electrons.
Each of the two oxygen atoms contributes 6 electrons, the carbon atom gives 4, and each hydrogen 1 electron.
The molecular weight in grams is determined by the empirical formula and the standard atomic weights of the elements. For chlorine, the standard atomic weight is 35.45.
The second and third molecular dimensions represent the size of the smallest rectangular hole that the molecule could go through. The first molecular dimension is the distance between the most distant atoms, the second dimension is the largest distance between two atoms in a plane perpendicular to the first dimension, and the third dimension is the largest distance between two atoms in direction perpendicular to the first two dimensions.
The total CPU time used up in this calculation. If restarts were used, then the total time for all the separate calculations
The number of separate SCF calculations run. In a geometry optimization, each cycle of optimization might involve more than one SCF, particularly if the potential energy surface is complicated.
The optimized geometry is printed. Note that the two dihedral angles were not marked for optimization and are therefore exactly the same as the starting angles (0 and 180 degrees)
The point-group of the optimized geometry. Normally the same as that of the starting geometry, but it can be different if the starting geometry was quantitatively incorrect
The energies, in electron volts, of the molecular orbitals. There are nine filled M.O.s in formic acid, so the highest filled M.O. has an energy of -11.8eV. The rest of the M.O.s are empty.
The "CHARGE" is the nuclear charge (a whole number) minus the number of electrons in each atomic orbital. "p-Pop" is the number of electrons in all three "p" orbitals. If an atom has a "d" shell, then there would be acolumn headed "d-Pop", and the numbers underneath would be the total "d" population.
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 O 0.0000000 0.000000 0.000000 2 C 1.2304588 * 0.000000 0.000000 3 O 1.3568332 * 117.681304 * 0.000000 2 1 0 4 H 0.9712524 * 110.582833 * 0.000000 3 2 1 5 H 1.1033197 * 129.967961 * 180.000000 2 1 3 Empirical Formula: C H2 O2 MOLECULAR POINT GROUP : Cs EIGENVALUES -40.62125 -36.77351 -24.87659 -18.96303 -18.12673 -16.19373 -14.67936 -12.58306 -11.81903 0.95713 2.28141 3.84205 5.09596 6.44101 NET ATOMIC CHARGES AND DIPOLE CONTRIBUTIONS ATOM NO. TYPE CHARGE No. of ELECS. s-Pop p-Pop 1 O -0.357283 6.3573 1.91393 4.44335 2 C 0.260327 3.7397 1.26671 2.47296 3 O -0.324044 6.3240 1.86042 4.46363 4 H 0.241808 0.7582 0.75819 5 H 0.179193 0.8208 0.82081
The molecular dipole, in Debye is given by the bottom right number, here 1.48. Dipole moments for ions are defined in terms of an accelerating frame: The ion is centered on its center of mass, and the dipole evaluated in the same way as for a molecule. If the center of mass changes, e.g. by doing isotopic substitution, then the ion's dipole would also change.
Atomic orbital electron populations for each orbital are output.
If this message is NOT printed at the end of a run, something has gone wrong.
DIPOLE X Y Z TOTAL POINT-CHG. 1.722 -0.361 0.000 1.759 HYBRID -0.243 0.298 0.000 0.384 SUM 1.479 -0.063 0.000 1.480 CARTESIAN COORDINATES NO. ATOM X Y Z 1 O 0.0000 0.0000 0.0000 2 C 1.2305 0.0000 0.0000 3 O 1.8608 1.2015 0.0000 4 H 1.2142 1.9263 0.0000 5 H 1.9392 -0.8456 0.0000 ATOMIC ORBITAL ELECTRON POPULATIONS 1.91393 1.13249 1.87986 1.43100 1.26671 0.88857 0.86899 0.71541 1.86042 1.42153 1.18851 1.85359 0.75819 0.82081 TOTAL CPU TIME: 0.03 SECONDS == MOPAC DONE ==