Compare vibrational frequencies for two calculations
for HNCS (Isothiocyanic acid)
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 |
A' |
A' |
|
3587 |
3517 |
70.3 |
1.020 |
|
1.097 |
1.091 |
0.007 |
1.006 |
|
528.17 |
283.97 |
244.21 |
1.860 |
|
|
|
|
|
2 |
A' |
A' |
|
2021 |
1955 |
66.6 |
1.034 |
|
7.821 |
8.680 |
-0.860 |
0.901 |
|
1083.46 |
590.21 |
493.25 |
1.836 |
|
|
|
|
|
3 |
A' |
A' |
|
798 |
852 |
-53.5 |
0.937 |
|
13.581 |
13.810 |
-0.229 |
0.983 |
|
31.53 |
2.30 |
29.23 |
13.685 |
|
|
|
|
|
4 |
A' |
A' |
|
495 |
612 |
-117.8 |
0.808 |
|
11.929 |
1.513 |
10.417 |
7.887 |
|
72.87 |
458.37 |
-385.50 |
0.159 |
|
|
|
|
|
5 |
A' |
A' |
|
306 |
427 |
-120.9 |
0.717 |
|
1.116 |
3.042 |
-1.926 |
0.367 |
|
561.14 |
64.22 |
496.92 |
8.737 |
|
|
|
|
|
6 |
A" |
A" |
|
475 |
441 |
34.5 |
1.078 |
|
7.173 |
4.904 |
2.269 |
1.463 |
|
0.97 |
5.64 |
-4.67 |
0.172 |
|
|
|
|
|
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.