SPARTAN CALCULATION ON AMMONIA, keyed to Version 06
(instructor's gloss in italics)
Run type: Geometry optimization
Model: RHF/3-21G
E(HF) =
-55.8722034 a.u.
(The reference, i.e. 0 Hartree, for E(HF) is 100% dissociation of the
molecule and 100% ionization of all electrons.)
(The value E(HF) converted into kcal/mol is
[-55.8722034 a.u.][2625.550 kJ/a.u.] = -146695.2636 kJ/mol.
round off yet.)
Don't
The total zero-point vibrational energy (ZPE) is 94.6056 kJ/mol
[Spartan now calculates the contribution of the ZPE from each
vibrational normal mode.]
Standard Thermodynamic quantities at
298.15 K and
1.00 atm
(With keywords, the calculation can be done for non-standard conditions
and a temperature other than 298.15 K.)
(The next section actually yields the contributions to H(T)- H(0 K at
T = 298.15 K.)
Ideal Gas
2.4789 kJ/mol (RT)
(The “Ideal Gas” term converts E to H for an ideal gas.
Recall that H = E + pV and pV = nRT for an ideal gas.)
Translational Enthalpy:
3.7184 kJ/mol (1.5RT)
Rotational Enthalpy:
3.7184 kJ/mol (1.5RT)
Vibrational Enthalpy:
0.1732 kJ/mol
Total value of H - H(0 K)
10.0889 kJ/mol
(The total enthalpy at 298.15 K, -146590.569 kJ/mol, is the sum of
electronic energy, -146695.2636 kJ/mol, the ZPE (94.6056 kJ/mol), and H
- H(0 K)(10.0889 kJ/mole). Use this final number in calculating H.
Note that the item in the totals row for H, 104.6946 kJ/mol, is the sum
of the ZPE and H - H(0 K).
Translational Entropy:
144.0999 J/mol-K
Rotational Entropy:
47.5594 J/mol-K
Vibrational Entropy:
0.7181 J/mol-K
Total Entropy:
192.3774 J/mol-K
(This is the standard entropy. The vibrational frequencies used to
calculate S, E, and H are not scaled!)
Vibrational Corrections:
Temp, Correction
Hv
104.6946 J/mol
(This cryptic item is ZPE + (H(T) - H(0 K)).)
Entropy correction (Hv-TSv):
47.3373 J/mol
(The second item is the thermal contribution to G.)
(Spartan now provides the vibrational, rotational, and translational
contributions to Cv. Recall for an ideal gas that Cp = Cv + R.)
thermo_prop_rev.doc