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

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at ROHF/6-31+G**

Scale factor	How many		Source
	Molecules	Vibrations
0.856 ± 0.155	39	62	cccbdb

Jump to histogram

Formula	Name	Mode	Symmetry	Frequency			Count
				Theory	Experiment	ratio	molecules	vibrations
CF3	Trifluoromethyl radical	1	A1	1206	1089	0.903	1	1
		2	A1	756	701	0.927	1	2
		3	E	1416	1260	0.890	1	3
		4	E	550	509	0.925	1	4
HCO	Formyl radical	1	A'	3005	2434	0.810	2	5
		2	A'	2138	1868	0.874	2	6
		3	A'	1253	1081	0.863	2	7
C3H3	Propargyl radical	1	A1	3638	3322	0.913	3	8
		6	B1	765	687	0.898	3	9
		7	B1	519	490	0.945	3	10
HO2	Hydroperoxy radical	1	A'	4087	3436	0.841	4	11
		2	A'	1601	1392	0.869	4	12
		3	A'	1251	1098	0.877	4	13
CH	Methylidyne	1	Σ	3061	2861	0.935	5	14
		1	Σ	3061	3145	1.027	5	15
		1	Σ	3061	2931	0.957	5	16
OH	Hydroxyl radical	1	Σ	4072	3738	0.918	6	17
NF2	Difluoroamino radical	1	A1	1252	1075	0.859	7	18
		2	A1	653	573	0.878	7	19
		3	B2	1168	942	0.807	7	20
CF	Fluoromethylidyne	1	Σ	1380	1308	0.948	8	21
CCl	carbon monochloride	1	Σ	876	877	1.001	9	22
OClO	Chlorine dioxide	1	A1	1060	946	0.892	10	23
		2	A1	509	448	0.880	10	24
		3	B2	1257	1110	0.883	10	25
SiF	silicon monofluoride	1	Σ	873	857	0.982	11	26
SiN	Silicon nitride	1	Σ	1306	1151	0.881	12	27
LiO	lithium oxide	1	Σ	844	815	0.966	13	28
BS	boron sulfide	1	Σ	1266	1180	0.932	14	29
AlS	Aluminum sulfide	1	Σ	679	617	0.908	15	30
CP	Carbon monophosphide	1	Σ	1447	1240	0.857	16	31
NaO	sodium monoxide	1	Σ	499	492	0.987	17	32
BeF	Beryllium monofluoride	1	Σ	1270	1247	0.982	18	33
PH2	Phosphino radical	1	A1	2553	2310	0.905	19	34
		2	A1	1241	1102	0.888	19	35
SiH3	silyl	1	A1	2342	2136	0.912	20	36
		2	A1	897	728	0.811	20	37
		3	E	2360	2185	0.926	20	38
		4	E	1020	922	0.904	20	39
NH2	Amino radical	1	A1	3638	3219	0.885	21	40
		2	A1	1639	1497	0.913	21	41
		3	B2	3740	3301	0.883	21	42
NH	Imidogen	1	Σ	3565	3283	0.921	22	43
		1	Σ	3565	3314	0.930	22	44
SiH	Silylidyne	1	Σ	2162	2043	0.945	23	45
BeCl	beryllium chloride	1	Σ	856	847	0.990	24	46
SO	Sulfur monoxide	1	Σ	1340	1151	0.859	25	47
SH	Mercapto radical	1	Σ	2878	2696	0.937	26	48
SiCl	Clorosilylidyne	1	Σ	526	536	1.019	27	49
NF	nitrogen fluoride	1	Σ	1237	1141	0.923	28	50
PH	phosphorus monohydride	1	Σ	2527	2364	0.935	29	51
		1	Σ	2527	2415	0.956	29	52
		1	Σ	2527	2403	0.951	29	53
MgH	magnesium monohydride	1	Σ	1575	1493	0.948	30	54
BH2	boron dihydride	2	A1	1127	954	0.846	31	55
AlH2	aluminum dihydride	1	A1	1962	1770	0.902	32	56
		2	A1	825	760	0.921	32	57
		3	B2	1975	1807	0.915	32	58
MgF	Magnesium monofluoride	1	Σ	728	712	0.978	33	59
MgCl	magnesium monochloride	1	Σ	455	462	1.016	34	60
ClO	Monochlorine monoxide	1	Σ	863	854	0.989	35	61
PF	phosphorus monofluoride	1	Σ	875	847	0.968	36	62
BeOH	beryllium hydroxide	2	A'	1304	1246	0.955	37	63
S2	Sulfur diatomic	1	Σg	816	726	0.890	38	64
ClS2	Sulfur chloride	1	A'	593	662	1.116	39	65
		2	A'	525	450	0.857	39	66
		3	A'	239	196	0.819	39	67

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.

	30
	25
	20
	15
	10
	5
	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