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

Vibrational frequency scaling factors

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

Scale factor	How many		Source
	Molecules	Vibrations
0.855 ± 0.155	37	60	cccbdb

Jump to histogram

Formula	Name	Mode	Symmetry	Frequency			Count
				Theory	Experiment	ratio	molecules	vibrations
CF3	Trifluoromethyl radical	1	A1	1220	1089	0.892	1	1
		2	A1	759	701	0.924	1	2
		3	E	1442	1260	0.874	1	3
		4	E	550	509	0.924	1	4
HCO	Formyl radical	1	A'	2976	2434	0.818	2	5
		2	A'	2154	1868	0.867	2	6
		3	A'	1264	1081	0.855	2	7
C3H3	Propargyl radical	1	A1	3644	3322	0.912	3	8
		6	B1	761	687	0.903	3	9
		7	B1	495	490	0.990	3	10
HO2	Hydroperoxy radical	1	A'	4085	3436	0.841	4	11
		2	A'	1603	1392	0.868	4	12
		3	A'	1252	1098	0.877	4	13
CH	Methylidyne	1	Σ	3029	2861	0.944	5	14
		1	Σ	3029	3145	1.038	5	15
		1	Σ	3029	2931	0.967	5	16
OH	Hydroxyl radical	1	Σ	4069	3738	0.918	6	17
NF2	Difluoroamino radical	1	A1	1270	1075	0.846	7	18
		2	A1	653	573	0.877	7	19
		3	B2	1193	942	0.790	7	20
CF	Fluoromethylidyne	1	Σ	1410	1308	0.927	8	21
CCl	carbon monochloride	1	Σ	872	877	1.006	9	22
OClO	Chlorine dioxide	1	A1	1070	946	0.883	10	23
		2	A1	508	448	0.882	10	24
		3	B2	1275	1110	0.870	10	25
SiF	silicon monofluoride	1	Σ	919	857	0.932	11	26
SiN	Silicon nitride	1	Σ	1319	1151	0.873	12	27
LiO	lithium oxide	1	Σ	888	815	0.917	13	28
BS	boron sulfide	1	Σ	1269	1180	0.930	14	29
AlS	Aluminum sulfide	1	Σ	681	617	0.906	15	30
CP	Carbon monophosphide	1	Σ	1453	1240	0.853	16	31
NaO	sodium monoxide	1	Σ	525	492	0.938	17	32
BeF	Beryllium monofluoride	1	Σ	1318	1247	0.947	18	33
PH2	Phosphino radical	1	A1	2554	2310	0.905	19	34
		2	A1	1243	1102	0.886	19	35
SiH3	silyl	1	A1	2340	2136	0.913	20	36
		2	A1	896	728	0.813	20	37
		3	E	2359	2185	0.926	20	38
		4	E	1018	922	0.905	20	39
NH2	Amino radical	1	A1	3627	3219	0.888	21	40
		2	A1	1669	1497	0.897	21	41
		3	B2	3725	3301	0.886	21	42
NH	Imidogen	1	Σ	3551	3283	0.924	22	43
		1	Σ	3551	3314	0.933	22	44
SiH	Silylidyne	1	Σ	2164	2043	0.944	23	45
BeCl	beryllium chloride	1	Σ	856	847	0.990	24	46
SH	Mercapto radical	1	Σ	2878	2696	0.937	25	47
SiCl	Clorosilylidyne	1	Σ	532	536	1.008	26	48
PH	phosphorus monohydride	1	Σ	2526	2364	0.936	27	49
		1	Σ	2526	2415	0.956	27	50
		1	Σ	2526	2403	0.951	27	51
MgH	magnesium monohydride	1	Σ	1577	1493	0.947	28	52
BH2	boron dihydride	2	A1	1143	954	0.834	29	53
AlH2	aluminum dihydride	1	A1	1960	1770	0.903	30	54
		2	A1	823	760	0.924	30	55
		3	B2	1974	1807	0.915	30	56
MgF	Magnesium monofluoride	1	Σ	779	712	0.914	31	57
MgCl	magnesium monochloride	1	Σ	459	462	1.006	32	58
ClO	Monochlorine monoxide	1	Σ	869	854	0.982	33	59
PF	phosphorus monofluoride	1	Σ	912	847	0.929	34	60
BeOH	beryllium hydroxide	2	A'	1312	1246	0.950	35	61
S2	Sulfur diatomic	1	Σg	819	726	0.887	36	62
ClS2	Sulfur chloride	1	A'	598	662	1.106	37	63
		2	A'	528	450	0.852	37	64
		3	A'	241	196	0.812	37	65

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.

	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