III.B.3.b. (XIII.C.2.)

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at MP2FU/6-31G(2df,p)

Scale factor	How many		Source
	Molecules	Vibrations
0.942 ± 0.036	11	69	cccbdb

Jump to histogram

Formula	Name	Mode	Symmetry	Frequency			Count
				Theory	Experiment	ratio	molecules	vibrations
C3H2N2	Malononitrile	1	A1	3130	2935	0.938	1	1
		2	A1	2243	2275	1.014	1	2
		3	A1	1475	1395	0.945	1	3
		4	A1	918	890	0.970	1	4
		5	A1	590	582	0.986	1	5
		6	A1	152	167	1.098	1	6
		7	A2	1286	1220	0.948	1	7
		8	A2	399	367	0.919	1	8
		9	B1	3186	2968	0.931	1	9
		10	B1	955	933	0.977	1	10
		11	B1	367	337	0.918	1	11
		12	B2	2248	2275	1.012	1	12
		13	B2	1362	1318	0.968	1	13
		14	B2	1010	982	0.972	1	14
		15	B2	392	366	0.934	1	15
C5H11N	Piperidine	1	A'	3565	3341	0.937	2	16
		2	A'	3166	2947	0.931	2	17
		3	A'	3159	2931	0.928	2	18
		4	A'	3151	2917	0.926	2	19
		5	A'	3099	2892	0.933	2	20
		6	A'	3098	2850	0.920	2	21
		7	A'	3095	2730	0.882	2	22
		8	A'	1538	1476	0.960	2	23
		9	A'	1521	1452	0.954	2	24
		10	A'	1519	1444	0.951	2	25
		11	A'	1420	1386	0.976	2	26
		12	A'	1410	1365	0.968	2	27
		13	A'	1367	1346	0.985	2	28
		14	A'	1312	1266	0.965	2	29
		15	A'	1214	1164	0.959	2	30
		16	A'	1082	1035	0.956	2	31
		17	A'	1046	1006	0.962	2	32
		18	A'	955	906	0.949	2	33
		19	A'	889	853	0.959	2	34
		20	A'	851	822	0.966	2	35
		21	A'	800	743	0.929	2	36
		22	A'	560	546	0.974	2	37
		23	A'	437	432	0.988	2	38
		24	A'	410	404	0.986	2	39
		25	A'	252	246	0.978	2	40
		26	A"	3162	2940	0.930	2	41
		27	A"	3152	2902	0.921	2	42
		28	A"	3097	2850	0.920	2	43
		29	A"	3094	2803	0.906	2	44
		30	A"	1519	1468	0.966	2	45
		31	A"	1516	1460	0.963	2	46
		32	A"	1495	1436	0.961	2	47
		33	A"	1408	1332	0.946	2	48
		34	A"	1397	1318	0.944	2	49
		35	A"	1369	1285	0.938	2	50
		36	A"	1328	1258	0.947	2	51
		37	A"	1248	1191	0.954	2	52
		38	A"	1177	1146	0.974	2	53
		39	A"	1144	1115	0.975	2	54
		40	A"	1098	1052	0.958	2	55
		41	A"	970	964	0.993	2	56
		42	A"	912	874	0.959	2	57
		43	A"	828	810	0.978	2	58
		44	A"	457	445	0.973	2	59
		45	A"	249	254	1.021	2	60
C2	Carbon diatomic	1	Σg	1668	1855	1.112	3	61
Si2	Silicon diatomic	1	Σg	615	511	0.831	4	62
NH	Imidogen	1	Σ	3453	3283	0.951	5	63
		1	Σ	3453	3314	0.960	5	64
SO	Sulfur monoxide	1	Σ	1020	1151	1.128	6	65
NF	nitrogen fluoride	1	Σ	1304	1141	0.875	7	66
PH	phosphorus monohydride	1	Σ	2485	2364	0.951	8	67
		1	Σ	2485	2415	0.972	8	68
		1	Σ	2485	2403	0.967	8	69
PF	phosphorus monofluoride	1	Σ	893	847	0.949	9	70
PCl	phosphorus chloride	1	Σ	599	577	0.963	10	71
S2	Sulfur diatomic	1	Σg	689	726	1.054	11	72

How do we calculate the scaling factor?

Histogram of vibrational frequency ratios

Ratios greater than 1.35 are in the 1.35 bin. Ratios less than 0.7 are in the 0.7 bin.

	50
	40
	30
	20
	10
	0
		0.70			0.75			0.80			0.85			0.90			0.95			1.00			1.05			1.10			1.15			1.20			1.25			1.30			1.35
Ratio of experimental frequency to calculated frequency