The heat capacity, Cp, of gas-phase systems can be predicted using the
calculated vibrational frequencies and moments of inertia and
the translational contributions. For monatomic species, only
translational contributions were used. The heat capacity at constant volume, Cv,
can be derived from Cv = Cp - R, where R=1.987 calories. All reference data is
taken from the Handbook of Chemistry and Physics.
Statistics for the set of 121 species
|
Average signed error: |
0.75 | 0.37* | |
|
Average unsigned error: |
1.48 | 1.12* | |
|
Root mean square error: |
3.14 | 1.64* |
*: Excluding the worst three results
Each of the PM6 results given below was generated by doing two calculations. First, the geometry was optimized, then a THERMO calculation was done. These calculations were done in a single run, with the data set having the form:
<keywords: none used>
<Name of species>
<Blank>
<Z-matrix: For examples, see: ref-data>
<Blank line>
OLDGEO THERMO(298,298,0)
<Blank line>
<Blank line>
Heat Capacities for Individual Species used in Preparing this Graph
(All values are in cal/(degree.mole))
|
Formula |
Molecule |
Exp. | PM6. | Diff |
|
B5H9 |
Pentaborane(9) |
23.80 |
28.76 |
-4.96 |
|
B5H11 |
Pentaborane(11) |
31.14 |
28.76 |
2.38 |
|
C2H2 |
Acetylene |
10.52 |
8.94 |
1.58 |
|
C3H6 |
Cyclopropane |
13.29 |
13.10 |
0.19 |
|
C3H8 |
Propane |
17.59 |
17.34 |
0.25 |
|
BC3H9 |
Trimethylborane |
21.15 |
24.73 |
-3.58 |
|
C6H6 |
Benzene |
19.69 |
19.45 |
0.24 |
|
C10H8 |
Naphthalene |
31.52 |
30.96 |
0.56 |
|
CNH5 |
Methylamine |
11.97 |
11.49 |
0.48 |
|
C2NH3 |
Acetonitrile |
12.48 |
12.11 |
0.37 |
|
C2NH7 |
Dimethylamine |
16.90 |
15.98 |
0.92 |
|
C2NH7 |
Ethylamine |
17.09 |
14.56 |
2.53 |
|
C3NH9 |
Trimethylamine |
21.94 |
21.45 |
0.49 |
|
C6NH7 |
Aniline |
25.79 |
24.75 |
1.04 |
|
C7NH9 |
m-Toluidine |
30.00 |
29.39 |
0.61 |
|
C7NH9 |
o-Toluidine |
31.11 |
29.20 |
1.91 |
|
C7NH9 |
p-Toluidine |
30.16 |
28.89 |
1.27 |
|
C2N2 |
Cyanogen |
13.58 |
12.15 |
1.43 |
|
CH2O |
Formaldehyde |
8.46 |
8.62 |
-0.16 |
|
CH4O |
Methanol |
10.54 |
11.10 |
-0.56 |
|
C2H2O |
Ketene |
12.38 |
11.82 |
0.56 |
|
C2H6O |
Dimethyl ether |
15.39 |
15.91 |
-0.52 |
|
C2H6O |
Ethanol |
15.68 |
16.24 |
-0.56 |
|
C3H6O |
Acetone |
17.81 |
18.68 |
-0.87 |
|
C3H6O |
Propanal |
19.29 |
17.86 |
1.43 |
|
C3H8O |
Isopropanol |
21.34 |
21.71 |
-0.37 |
|
C3H8O |
Propanol |
20.46 |
19.06 |
1.40 |
|
C4H4O |
Furan |
15.63 |
15.71 |
-0.08 |
|
C4H6O |
2,3-Dihydrofuran |
19.07 |
17.85 |
1.22 |
|
C2H2O2 |
trans Glyoxal |
14.48 |
14.37 |
0.11 |
|
C2H4O2 |
Acetic acid |
15.15 |
16.83 |
-1.68 |
|
C2H6O2 |
Ethylene glycol |
19.77 |
16.70 |
3.07 |
|
C3H6O2 |
Methyl acetate |
20.55 |
18.57 |
1.98 |
|
CNH3O2 |
Nitromethane |
13.26 |
14.66 |
-1.40 |
|
C2NH5O2 |
Nitroethane |
18.88 |
17.46 |
1.42 |
|
C6NH5O2 |
Nitrobenzene |
28.78 |
27.74 |
1.04 |
|
CNH3O3 |
Methyl nitrate |
18.31 |
17.66 |
0.65 |
|
C3NH7O3 |
Propyl nitrate |
29.44 |
24.27 |
5.17 |
|
CN2H2O4 |
Dinitromethane |
20.65 |
21.82 |
-1.17 |
|
CN4O8 |
Tetranitromethane |
42.09 |
34.69 |
7.40 |
|
C3N3H5O9 |
Glycerol trinitrate |
55.98 |
37.05 |
18.93 |
|
C5N4H8O12 |
Pentaerythritol tetranitrate |
70.45 |
49.03 |
21.42 |
|
F |
Fluorine, atom |
5.42 |
4.97 |
0.45 |
|
CH3F |
Fluoromethane |
8.96 |
9.17 |
-0.21 |
|
C2HF |
Fluoroacetylene |
12.52 |
11.22 |
1.30 |
|
C2H5F |
Fluoroethane |
14.00 |
13.81 |
0.19 |
|
CNF |
Cyanogen fluoride |
9.99 |
9.33 |
0.66 |
|
F2 |
Fluorine |
7.45 |
7.44 |
0.01 |
|
OF2 |
Difluorine oxide |
10.35 |
9.77 |
0.58 |
|
COF2 |
Carbonyl fluoride |
11.19 |
11.89 |
-0.70 |
|
C2H3F3 |
1,1,1-Trifluoroethane |
18.69 |
18.62 |
0.07 |
|
NF3 |
Nitrogen trifluoride |
12.76 |
12.58 |
0.18 |
|
C2NF3 |
Trifluoroacetonitrile |
18.62 |
18.57 |
0.05 |
|
CF4 |
Carbon tetrafluoride |
14.60 |
15.50 |
-0.90 |
|
C2F6 |
Hexafluoroethane |
25.50 |
23.95 |
1.55 |
|
NaF |
Sodium fluoride |
7.65 |
8.10 |
-0.45 |
|
SiCH6 |
Methylsilane |
16.99 |
16.27 |
0.72 |
|
SiC3H10 |
Trimethylsilane |
28.18 |
29.01 |
-0.83 |
|
SiC4H12 |
Tetramethylsilane |
34.39 |
36.96 |
-2.57 |
|
Si2C6H18O |
Hexamethyldisiloxane |
57.00 |
55.67 |
1.33 |
|
PF3 |
Phosphorus trifluoride |
14.02 |
14.79 |
-0.77 |
|
POF3 |
Phosphorus oxyfluoride |
16.44 |
18.14 |
-1.70 |
|
CH4S |
Thiomethanol |
12.02 |
12.05 |
-0.03 |
|
C2H6S |
Thioethanol |
17.71 |
16.90 |
0.81 |
|
C3H6S |
Thietane |
16.32 |
16.48 |
-0.16 |
|
C4H10S |
Diethyl thioether |
27.96 |
23.71 |
4.25 |
|
C2H6SO2 |
Dimethyl sulfone |
23.90 |
23.99 |
-0.09 |
|
SO2F2 |
Sulfuryl fluoride |
15.77 |
18.00 |
-2.23 |
|
CH3Cl |
Methyl chloride |
9.75 |
9.89 |
-0.14 |
|
C2HCl |
Chloroacetylene |
12.98 |
11.59 |
1.39 |
|
C2H5Cl |
Chloroethane |
15.01 |
14.60 |
0.41 |
|
CNCl |
Cyanogen chloride |
10.75 |
10.24 |
0.51 |
|
ClF |
Chlorine fluoride |
7.67 |
10.24 |
-2.57 |
|
ClF3 |
Chlorine trifluoride |
15.27 |
15.66 |
-0.39 |
|
Cl2 |
Chlorine |
8.10 |
8.03 |
0.07 |
|
CH2Cl2 |
Dichloromethane |
12.19 |
12.27 |
-0.08 |
|
CCl2O |
Carbonyl chloride |
13.79 |
13.70 |
0.09 |
|
SCl2O2 |
Sulfuryl chloride |
18.40 |
19.21 |
-0.81 |
|
BCl3 |
Boron trichloride |
14.99 |
19.21 |
-4.22 |
|
C2H3Cl3 |
1,1,1-Trichloroethane |
22.30 |
21.81 |
0.49 |
|
SiHCl3 |
Trichlorosilane |
18.12 |
18.60 |
-0.48 |
|
PCl3 |
Phosphorus trichloride |
17.16 |
17.31 |
-0.15 |
|
PCl3O |
Phosphorus oxychloride |
20.29 |
20.96 |
-0.67 |
|
SiCl4 |
Silicon tetrachloride |
21.58 |
22.12 |
-0.54 |
|
PCl5 |
Phosphorus pentachloride |
26.96 |
23.58 |
3.38 |
|
Ar |
Argon, atom |
4.97 |
4.97 |
0.00 |
|
TiCl4 |
Titanium tetrachloride |
22.80 |
19.87 |
2.93 |
|
CrO3 |
Chromium(VI) trioxide |
13.38 |
14.39 |
-1.01 |
|
CrCl2O2 |
Chromium dioxide dichloride |
20.20 |
21.10 |
-0.90 |
|
GeH3F |
Fluorogermane |
11.33 |
13.02 |
-1.69 |
|
GeCl4 |
Germanium tetrachloride |
22.97 |
23.48 |
-0.51 |
|
AsH3 |
Arsine |
9.11 |
9.03 |
0.08 |
|
AsF3 |
Arsenic trifluoride |
15.68 |
16.23 |
-0.55 |
|
AsCl3 |
Arsenic trichloride |
18.09 |
18.12 |
-0.03 |
|
HBr |
Hydrogen bromide |
6.96 |
6.96 |
0.00 |
|
CH3Br |
Bromomethane |
10.13 |
10.41 |
-0.28 |
|
C2HBr |
Bromoacetylene |
13.31 |
11.91 |
1.40 |
|
C2H5Br |
Bromoethane |
15.42 |
15.09 |
0.33 |
|
CNBr |
Cyanogen bromide |
11.21 |
10.79 |
0.42 |
|
NBrO |
Nitrosyl bromide |
10.87 |
10.05 |
0.82 |
|
BrF |
Bromine fluoride |
7.89 |
7.71 |
0.18 |
|
BrF3 |
Bromine trifluoride |
15.92 |
16.20 |
-0.28 |
|
BrF5 |
Bromine pentafluoride |
23.80 |
22.23 |
1.57 |
|
SiH3Br |
Bromosilane |
12.62 |
13.15 |
-0.53 |
|
BrCl |
Bromine chloride |
8.37 |
8.32 |
0.05 |
|
GeH3Br |
Bromogermane |
13.48 |
14.11 |
-0.63 |
|
Br2 |
Bromine |
8.60 |
8.59 |
0.01 |
|
CBr2F2 |
Difluorodibromomethane |
18.40 |
18.56 |
-0.16 |
|
SiHBr3 |
Tribromosilane |
19.31 |
19.84 |
-0.53 |
|
AsBr3 |
Arsenic tribromide |
18.93 |
15.08 |
3.85 |
|
NbCl5 |
Niobium(V) pentachloride |
28.87 |
24.61 |
4.26 |
|
MoF6 |
Molybdenum(VI) hexafluoride |
28.82 |
24.94 |
3.88 |
|
SnCl4 |
Tin tetrachloride |
23.49 |
19.89 |
3.60 |
|
CH3I |
Methyl iodide |
10.54 |
10.95 |
-0.41 |
|
C2H5I |
Iodoethane |
15.99 |
15.53 |
0.46 |
|
CIF3 |
Trifluoroiodomethane |
16.95 |
17.35 |
-0.40 |
|
IBr |
Iodine bromide |
8.70 |
8.75 |
-0.05 |
|
C2I2 |
Diiodoacetylene |
16.80 |
15.99 |
0.81 |
|
BI3 |
Boron triiodide |
16.92 |
13.05 |
3.87 |
|
CsHO |
Cesium hydroxide |
11.88 |
11.33 |
0.55 |
|
WF6 |
Tungsten hexafluoride |
28.44 |
25.55 |
2.89 |
|
BiCl3 |
Bismuth trichloride |
19.05 |
14.91 |
4.14 |