Compare vibrational frequencies for two calculations
for Si2H2 (disilyne)
A =
HF/6-31G*
B =
MP2/6-31G*
scale factors=0.8985, 0.943
|
symmetry |
|
frequency (cm-1) |
|
reduced mass (amu) |
|
IR Intensity (km mol-1) |
|
Raman Activity (Å4/u) |
mode number |
A |
B |
|
A |
B |
diff. |
ratio |
|
A |
B |
diff. |
ratio |
|
A |
B |
diff. |
ratio |
|
A |
B |
diff. |
ratio |
1 |
Σg |
Σg |
|
2260 |
2268 |
-8.1 |
0.996 |
|
1.051 |
1.051 |
0.000 |
1.000 |
|
0.00 |
0.00 |
0.00 |
|
|
237.04 |
286.42 |
-49.38 |
0.828 |
2 |
Σg |
Σg |
|
749 |
689 |
60.0 |
1.087 |
|
13.009 |
13.041 |
-0.032 |
0.998 |
|
0.00 |
0.00 |
0.00 |
|
|
125.88 |
44.77 |
81.10 |
2.811 |
3 |
Σu |
Σu |
|
2256 |
2266 |
-9.9 |
0.996 |
|
1.043 |
1.043 |
0.000 |
1.000 |
|
13.11 |
1.41 |
11.70 |
9.312 |
|
0.00 |
0.00 |
0.00 |
|
4 |
Πg |
Πg |
|
494i |
560i |
66.8 |
0.881 |
|
1.224 |
1.220 |
0.004 |
1.003 |
|
0.00 |
0.00 |
0.00 |
|
|
100.86 |
51.07 |
49.79 |
1.975 |
5 |
Πg |
Πg |
|
494i |
560i |
66.8 |
0.881 |
|
1.224 |
1.220 |
0.004 |
1.003 |
|
0.00 |
0.00 |
0.00 |
|
|
100.86 |
51.07 |
49.79 |
1.975 |
6 |
Πu |
Πu |
|
471 |
381 |
90.2 |
1.237 |
|
1.043 |
1.043 |
0.000 |
1.000 |
|
0.05 |
3.28 |
-3.23 |
0.015 |
|
0.00 |
0.00 |
0.00 |
|
7 |
Πu |
Πu |
|
471 |
381 |
90.2 |
1.237 |
|
1.043 |
1.043 |
0.000 |
1.000 |
|
0.05 |
3.28 |
-3.23 |
0.015 |
|
0.00 |
0.00 |
0.00 |
|
scaled by |
|
|
0.8985 |
0.943 |
19 08 20 15 07
See section III.C.1 List or set vibrational scaling factors
to change the scale factors used here.
See section III.C.2
Calculate a vibrational scaling factor for a given set of molecules
to determine the least squares best scaling factor.