(move the cursor over the file to see what the parts are)
A FORCE calculation requires an optimized geometry, so the first part of this output is a normal MOPAC optimization.
Scroll down to the line "START OF FORCE CALCULATION OUTPUT" (about half way down) to see the FORCE calculation output.
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******************************************************************************* ** Site#: 10 For non-commercial use only Version 7.101W ** ******************************************************************************* ** Cite this work as: MOPAC2007, James J. P. Stewart, Stewart Computational ** ** Chemistry, Version 7.101W web: HTTP://OpenMOPAC.net Days remaining: 363 ** ******************************************************************************* ** ** ** MOPAC2007 ** ** ** ******************************************************************************* PM6 CALCULATION RESULTS ******************************************************************************* * CALCULATION DONE: Wed Apr 11 11:13:27 2007 * * SYMMETRY - SYMMETRY CONDITIONS TO BE IMPOSED * T= - A TIME OF 172800.0 SECONDS REQUESTED * DUMP=N - RESTART FILE WRITTEN EVERY 7200.000 SECONDS ******************************************************************************* PARAMETER DEPENDENCE DATA REFERENCE ATOM FUNCTION NO. DEPENDENT ATOM(S) 3 1 4 3 2 4 DESCRIPTIONS OF THE FUNCTIONS USED 1 BOND LENGTH IS SET EQUAL TO THE REFERENCE BOND LENGTH 2 BOND ANGLE IS SET EQUAL TO THE REFERENCE BOND ANGLE SYMMETRY Formaldehyde 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 1.2108153 * 0.000000 0.000000 1 0 0 3 H 1.0974996 * 122.023501 * 0.000000 2 1 0 4 H 1.0974996 122.023501 180.000000 2 1 3 CARTESIAN COORDINATES NO. ATOM X Y Z 1 O 0.0000 0.0000 0.0000 2 C 1.2108 0.0000 0.0000 3 H 1.7928 0.9305 0.0000 4 H 1.7928 -0.9305 0.0000 H (PM6): J. J. P. Stewart J. Mol. Mod. (to be submitted)! C (PM6): J. J. P. Stewart J. Mol. Mod. (to be submitted)! O (PM6): J. J. P. Stewart J. Mol. Mod. (to be submitted)! Empirical Formula: C H2 O MOLECULAR POINT GROUP : C2v RHF CALCULATION, NO. OF DOUBLY OCCUPIED LEVELS = 6 ------------------------------------------------------------------------------- SYMMETRY Formaldehyde GRADIENTS WERE INITIALLY ACCEPTABLY SMALL SCF FIELD WAS ACHIEVED PM6 CALCULATION MOPAC2007 (Version: 7.101W) Wed Apr 11 11:13:27 2007 No. of days left = 363 FINAL HEAT OF FORMATION = -20.69775 KCAL = -86.59937 KJ TOTAL ENERGY = -440.23219 EV ELECTRONIC ENERGY = -825.76440 EV POINT GROUP: C2v CORE-CORE REPULSION = 385.53221 EV COSMO AREA = 60.76 SQUARE ANGSTROMS COSMO VOLUME = 42.60 CUBIC ANGSTROMS IONIZATION POTENTIAL = 10.20363 NO. OF FILLED LEVELS = 6 MOLECULAR WEIGHT = 30.026 MOLECULAR DIMENSIONS (Angstroms) Atom Atom Distance H 3 O 1 2.01987 H 4 O 1 1.65176 O 1 C 2 0.00000 SCF CALCULATIONS = 1 COMPUTATION TIME = 0.000 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 O 0.0000000 0.000000 0.000000 2 C 1.2108153 * 0.000000 0.000000 1 0 0 3 H 1.0974996 * 122.023501 * 0.000000 2 1 0 4 H 1.0974996 122.023501 180.000000 2 1 3 Empirical Formula: C H2 O MOLECULAR POINT GROUP : C2v EIGENVALUES -32.00372 -23.55732 -17.17527 -15.14025 -14.75913 -10.20363 0.03208 4.08556 4.45994 4.74270 NET ATOMIC CHARGES AND DIPOLE CONTRIBUTIONS ATOM NO. TYPE CHARGE No. of ELECS. s-Pop p-Pop 1 O -0.422510 6.4225 1.85390 4.56861 2 C 0.236385 3.7636 1.14506 2.61855 3 H 0.093063 0.9069 0.90694 4 H 0.093063 0.9069 0.90694 DIPOLE X Y Z TOTAL POINT-CHG. 2.978 0.000 0.000 2.978 HYBRID -0.160 0.000 0.000 0.160 SUM 2.818 0.000 0.000 2.818 CARTESIAN COORDINATES NO. ATOM X Y Z 1 O 0.0000 0.0000 0.0000 2 C 1.2108 0.0000 0.0000 3 H 1.7928 0.9305 0.0000 4 H 1.7928 -0.9305 0.0000 ATOMIC ORBITAL ELECTRON POPULATIONS 1.85390 1.29031 1.93516 1.34314 1.14506 0.89773 1.06397 0.65686 0.90694 0.90694 TOTAL CPU TIME: 0.02 SECONDS == MOPAC DONE ==
START OF FORCE CALCULATION OUTPUT
******************************************************************************* ** Site#: 10 For non-commercial use only Version 7.101W ** ******************************************************************************* ** Cite this work as: MOPAC2007, James J. P. Stewart, Stewart Computational ** ** Chemistry, Version 7.101W web: HTTP://OpenMOPAC.net Days remaining: 363 ** ******************************************************************************* ** ** ** MOPAC2007 ** ** ** ******************************************************************************* PM6 CALCULATION RESULTS ******************************************************************************* * CALCULATION DONE: Wed Apr 11 11:13:27 2007 * * OLDGEO - PREVIOUS GEOMETRY TO BE USED * FORCE - FORCE CALCULATION SPECIFIED * T= - A TIME OF 172800.0 SECONDS REQUESTED * DUMP=N - RESTART FILE WRITTEN EVERY 7200.000 SECONDS ******************************************************************************* oldgeo force
The starting geometry for the FORCE calculation is the optimized geometry from the previous
calculation. The use of a double calculation - first a geometry optimization, then a FORCE calculation using the optimized geometry -
is the easiest way to calculate the vibrations.
Keyword FORCE instructs MOPAC to calculate the vibrational freqencies.
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Before the normal modes are calculated, a check is done to ensure that the structure is at a
stationary point, this can be either a ground state or a transition state geometry
The gradient norm is acceptably low, so the calculation can continue. If it was high,
then the calculation would be stopped and a warning given. To over-ride this check, use keyword "LET"
The rotational constants depend on the geometry only.
The rotational constants can be re-written as the Principal Moments of Inertia.
To make the normal modes easier to see, the molecule is orientated along
its Principal Moments of Inertia. The smallest is "X", then "Y" then"Z". If you do not want reorientation done,
add keyword "NOREOR".
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When present, symmetry is used to speed up the construction of the Hessian or force matrix.
First, the point-group is identified, then the symmetry operations of the group are used to accelerate the construction of the Hessian.
If you do NOT want symmetry to be used, add keyword "NOSYM"
For all systems, the Hessian is of size 3N by 3N, where N is the number of atoms.
Constructing the Hessian is a slow operation, so each of the 3N steps is printed as it is done. When symmetry is used to speed up the
calculation, the text "TIME = n.nn SECS," will not be printed
The vector sum of the force constants is printed. If the full force matrix is needed, add keyword "DEBUGFORCE"
The zero point energy is calculated from N*h*c/(2x10^(10)*4.184)*sum_i (nu_i), where nu_i are the
vibrational frequencies, that is, it is the sum of (1/2)h*mu. mu = c*nu
The (3N-6) non-trivial modes or normal coordinates are printed, along with their vibrational frequencies and symmetry labels.
Each mode is represented by the mass-weighted normalized x, y, and z velocity components of each atom when the mode goes through the equilibrium geometry.
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This analysis is the easiest way to describe each vibration. The first number in the energy
contribution is the normalized percentage contribution of the diatomic term to the energy of vibration; this adds to 100. The number in parentheses
is the un-normalized contribution. The RADIAL term gives the percentage stretch; the rest is bending or tangential motion.
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Force constants, in internal coordinates, are printed, if the data was supplied in internal coordinates.
This is useful when individual force constants in a molecule are wanted. Be careful when calculating internal force constants for cyclic systems,
e.g., benzene.
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