CCCBDB calculation results Page

State	Conformation	minimum conformation	conformer description	state description
1	1	yes	C2	¹A^'

Energy calculated at MP2/CEP-31G*

	hartrees
Energy at 0K	-40.624894
Energy at 298.15K
HF Energy	-39.885476
Nuclear repulsion energy	135.395497

The energy at 298.15K was derived from the energy at 0K and an integrated heat capacity that used the calculated vibrational frequencies.

Vibrational Frequencies calculated at MP2/CEP-31G*

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3265	3100	21.28
2	A'	3184	3023	51.43
3	A'	3179	3018	10.52
4	A'	3178	3017	29.60
5	A'	3172	3012	75.73
6	A'	3104	2947	16.57
7	A'	3080	2925	31.95
8	A'	3074	2918	18.56
9	A'	1712	1625	8.88
10	A'	1536	1459	4.50
11	A'	1534	1456	13.62
12	A'	1519	1442	12.19
13	A'	1471	1397	1.87
14	A'	1448	1375	5.44
15	A'	1438	1366	5.40
16	A'	1365	1296	3.00
17	A'	1333	1266	0.71
18	A'	1211	1150	2.94
19	A'	1124	1067	13.58
20	A'	1013	962	1.61
21	A'	985	935	0.52
22	A'	924	877	1.33
23	A'	745	708	1.16
24	A'	517	491	1.16
25	A'	434	412	0.71
26	A'	330	313	0.21
27	A'	282	268	0.26
28	A'	265	252	0.11
29	A"	3177	3016	5.10
30	A"	3170	3010	16.51
31	A"	3162	3002	26.39
32	A"	3073	2918	32.85
33	A"	1526	1449	0.31
34	A"	1514	1437	2.23
35	A"	1503	1427	10.53
36	A"	1429	1356	6.20
37	A"	1365	1296	1.05
38	A"	1156	1098	4.00
39	A"	1070	1016	0.00
40	A"	987	937	0.32
41	A"	944	896	1.59
42	A"	846	803	70.94
43	A"	738	701	0.42
44	A"	536	509	8.17
45	A"	271	257	0.07
46	A"	207	197	0.55
47	A"	166	157	0.43
48	A"	19i	18i	0.05

Unscaled Zero Point Vibrational Energy (zpe) 36621.1 cm^-1
Scaled (by 0.9494) Zero Point Vibrational Energy (zpe) 34768.1 cm^-1
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.

Rotational Constants (cm^-1) from geometry optimized at MP2/CEP-31G*

A	B	C
0.14463	0.08174	0.08049

See section I.F.4 to change rotational constant units

Geometric Data calculated at MP2/CEP-31G*

Point Group is C_s

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-1.785	-1.076	0.000
C2	-0.474	-0.669	0.000
C3	-0.124	0.817	0.000
C4	0.665	-1.684	0.000
C5	0.665	1.221	1.270
C6	0.665	1.221	-1.270
H7	-2.055	-2.139	0.000
H8	-2.605	-0.348	0.000
H9	-1.079	1.375	0.000
H10	0.267	-2.714	0.000
H11	1.307	-1.564	-0.891
H12	1.307	-1.564	0.891
H13	0.810	2.317	1.296
H14	0.122	0.920	2.185
H15	1.664	0.750	1.287
H16	0.810	2.317	-1.296
H17	0.122	0.920	-2.185
H18	1.664	0.750	-1.287

Atom - Atom Distances (Å)

	C1	C2	C3	C4	C5	C6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17	H18
C1		1.3727	2.5192	2.5243	3.5910	3.5910	1.0963	1.0966	2.5510	2.6253	3.2552	3.2552	4.4645	3.5213	4.1097	4.4645	3.5213	4.1097
C2	1.3727		1.5268	1.5260	2.5463	2.5463	2.1587	2.1543	2.1312	2.1750	2.1840	2.1840	3.4995	2.7669	2.8710	3.4995	2.7669	2.8710
C3	2.5192	1.5268		2.6225	1.5486	1.5486	3.5311	2.7409	1.1063	3.5522	2.9170	2.9170	2.1913	2.2010	2.2036	2.1913	2.2010	2.2036
C4	2.5243	1.5260	2.6225		3.1710	3.1710	2.7576	3.5321	3.5211	1.1035	1.1053	1.1053	4.2087	3.4428	2.9293	4.2087	3.4428	2.9293
C5	3.5910	2.5463	1.5486	3.1710		2.5406	4.5058	3.8424	2.1627	4.1538	3.5833	2.8831	1.1059	1.1051	1.1048	2.7944	3.5104	2.7856
C6	3.5910	2.5463	1.5486	3.1710	2.5406		4.5058	3.8424	2.1627	4.1538	2.8831	3.5833	2.7944	3.5104	2.7856	1.1059	1.1051	1.1048
H7	1.0963	2.1587	3.5311	2.7576	4.5058	4.5058		1.8737	3.6469	2.3922	3.5259	3.5259	5.4540	4.3445	4.8821	5.4540	4.3445	4.8821
H8	1.0966	2.1543	2.7409	3.5321	3.8424	3.8424	1.8737		2.3011	3.7208	4.1925	4.1925	4.5212	3.7172	4.5916	4.5212	3.7172	4.5916
H9	2.5510	2.1312	1.1063	3.5211	2.1627	2.1627	3.6469	2.3011		4.3043	3.8888	3.8888	2.4769	2.5342	3.0934	2.4769	2.5342	3.0934
H10	2.6253	2.1750	3.5522	1.1035	4.1538	4.1538	2.3922	3.7208	4.3043		1.7886	1.7886	5.2234	4.2428	3.9503	5.2234	4.2428	3.9503
H11	3.2552	2.1840	2.9170	1.1053	3.5833	2.8831	3.5259	4.1925	3.8888	1.7886		1.7823	4.4825	4.1276	3.1976	3.9335	3.0413	2.3743
H12	3.2552	2.1840	2.9170	1.1053	2.8831	3.5833	3.5259	4.1925	3.8888	1.7886	1.7823		3.9335	3.0413	2.3743	4.4825	4.1276	3.1976
H13	4.4645	3.4995	2.1913	4.2087	1.1059	2.7944	5.4540	4.5212	2.4769	5.2234	4.4825	3.9335		1.7928	1.7847	2.5921	3.8132	3.1396
H14	3.5213	2.7669	2.2010	3.4428	1.1051	3.5104	4.3445	3.7172	2.5342	4.2428	4.1276	3.0413	1.7928		1.7923	3.8132	4.3697	3.8026
H15	4.1097	2.8710	2.2036	2.9293	1.1048	2.7856	4.8821	4.5916	3.0934	3.9503	3.1976	2.3743	1.7847	1.7923		3.1396	3.8026	2.5739
H16	4.4645	3.4995	2.1913	4.2087	2.7944	1.1059	5.4540	4.5212	2.4769	5.2234	3.9335	4.4825	2.5921	3.8132	3.1396		1.7928	1.7847
H17	3.5213	2.7669	2.2010	3.4428	3.5104	1.1051	4.3445	3.7172	2.5342	4.2428	3.0413	4.1276	3.8132	4.3697	3.8026	1.7928		1.7923
H18	4.1097	2.8710	2.2036	2.9293	2.7856	1.1048	4.8821	4.5916	3.0934	3.9503	2.3743	3.1976	3.1396	3.8026	2.5739	1.7847	1.7923

picture of 2,3-dimethylbut-1-ene state 1 conformation 1

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C3	120.560	C1	C2	C4	121.018
C2	C1	H7	121.523	C2	C1	H8	121.077
C2	C3	C5	111.777	C2	C3	C6	111.777
C2	C3	H9	106.993	C2	C4	H10	110.586
C2	C4	H11	111.189	C2	C4	H12	111.189
C3	C2	C4	118.422	C3	C5	H13	110.157
C3	C5	H14	110.973	C3	C5	H15	111.187
C3	C6	H16	110.157	C3	C6	H17	110.973
C3	C6	H18	111.187	C5	C3	C6	110.221
C5	C3	H9	107.934	C6	C3	H9	107.934
H7	C1	H8	117.400	H10	C4	H11	108.141
H10	C4	H12	108.141	H11	C4	H12	107.459
H13	C5	H14	108.354	H13	C5	H15	107.666
H14	C5	H15	108.393	H16	C6	H17	108.354
H16	C6	H18	107.666	H17	C6	H18	108.393

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability

All results from a given calculation for C₆H₁₂ (2,3-dimethylbut-1-ene)

using model chemistry: MP2/CEP-31G*

States and conformations

	Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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All results from a given calculation for C6H12 (2,3-dimethylbut-1-ene)

using model chemistry: MP2/CEP-31G*

States and conformations

All results from a given calculation for C₆H₁₂ (2,3-dimethylbut-1-ene)