Carlier Group Gaussian User Manual - Virginia Tech

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36 Carlier Group Gaussian User Manual electronic energy, a BSSE-corrected electronic energy, or an energy that includes all three! ii. But if you prefer to get the sum of corrections and electronic energy: pcarlier@inferno2:~/run> egrep Sum h0498.out Sum of Mulliken charges= -0.00000 Sum of Mulliken charges= -0.00000 Sum of Mulliken charges= -0.00000 Sum of Mulliken charges= -0.00000 Sum of Mulliken charges= -0.00000 Sum of Mulliken charges= -0.00000 Sum of APT charges= -0.00000 Sum of APT charges= -0.00000 Sum of electronic and zero-point Energies= -234.501264 Sum of electronic and thermal Energies= -234.495786 Sum of electronic and thermal Enthalpies= -234.494842 Sum of electronic and thermal Free Energies= -234.529228 iii. To see detailed entropy information, type more h0498.out then within the more program, type /Thermal and you will get the following output (truncated at the bottom: /Thermal ...skipping Zero-point correction= 0.147025 (Hartree/Particle) Thermal correction to Energy= 0.152503 Thermal correction to Enthalpy= 0.153447 Thermal correction to Gibbs Free Energy= 0.119061 Sum of electronic and zero-point Energies= -234.501264 Sum of electronic and thermal Energies= -234.495786 Sum of electronic and thermal Enthalpies= -234.494842 Sum of electronic and thermal Free Energies= -234.529228 E (Thermal) CV S KCal/Mol Cal/Mol-Kelvin Cal/Mol-Kelvin Total 95.697 21.296 72.372 Electronic 0.000 0.000 0.000 Translational 0.889 2.981 39.129 Rotational 0.889 2.981 24.809 Vibrational 93.919 15.335 8.433
Carlier Group Gaussian User Manual 37 D. Obtaining thermodynamic parameters at any temperature Gaussian ’09 calculates thermodynamic parameters at STP (Standard Temperature and Pressure) which means 298.150 K and 1atm. Often, we desire these values at much lower temperatures. There is a utility built into Gaussian ’09 called freqchk. This utility pulls thermodynamic values from filename.chk, and recalculates them for whatever temperatures and/or pressures you specify. This is an easy method for changing temperature and pressure after the calculation is completed Example: (user input in bold) pcarlier@charon1:~/sgi/run> freqchk Checkpoint file? j0007.chk Write Hyperchem files? n Temperature (K)? [0=>298.15] 193 Pressure (Atm)? [0=>1 atm] 0 Scale factor for frequencies during thermochemistry? [0=>1/1.12] 0.9804 Do you want to use the principal isotope masses? [Y]: y --------------------------------------------------------------------- Center Atomic Coordinates (Angstroms) Number Number X Y Z --------------------------------------------------------------------- 1 12 -0.286520 -0.578356 -1.611669 2 17 -0.830292 -1.383436 0.657515 3 8 -2.141684 0.267642 -2.142086 (lots of data after this, then) Project out gradient direction? [N] n Notes on using this utility: Write Hyperchem files? I enter ‘no’. Temperature (K) [0=>298.15]: Entering 0 means the system will automatically assume you want to use the standard temperature of 298.150K (default temp). Any other temperature will be read as is (remember—use degrees Kelvin). Pressure (Atm)> [0=>1 atm]: As above, entering 0 will signify 1 atm (default pressure). Scaling factor [0=>1/1.12]: This value is specific to the method/basis set of the calculation. For each level of calculation there is an appropriate scaling factor to be applied. Entering 1, signifies no scaling. B3LYP/6-31G* = 0.9804 Principal isotope masses? Select yes for this question. Otherwise it will ask you what mass you want to use for each atom.
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Carlier Group Gaussian User Manual - Virginia Tech

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