CCCBDB calculation results Page

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

Energy calculated at MP2/CEP-121G

	hartrees
Energy at 0K	-40.348226
Energy at 298.15K	-40.360362
HF Energy	-39.801827
Nuclear repulsion energy	134.524520

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-121G

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3178	3102	35.73
2	A'	3074	3001	44.90
3	A'	3072	2999	21.49
4	A'	3066	2992	26.26
5	A'	3062	2989	119.93
6	A'	2975	2903	13.42
7	A'	2962	2891	45.13
8	A'	2956	2885	21.39
9	A'	1644	1605	8.85
10	A'	1540	1503	2.76
11	A'	1532	1495	14.50
12	A'	1526	1489	8.45
13	A'	1472	1436	1.08
14	A'	1454	1419	8.03
15	A'	1447	1412	6.78
16	A'	1356	1323	3.42
17	A'	1320	1288	0.46
18	A'	1210	1181	2.34
19	A'	1124	1097	8.56
20	A'	1022	997	0.94
21	A'	975	951	0.23
22	A'	896	874	1.05
23	A'	716	699	0.70
24	A'	516	504	0.80
25	A'	435	425	0.59
26	A'	325	317	0.18
27	A'	276	269	0.20
28	A'	241	235	0.15
29	A"	3063	2990	18.99
30	A"	3058	2985	9.84
31	A"	3048	2975	35.38
32	A"	2954	2883	38.71
33	A"	1529	1493	0.01
34	A"	1510	1474	4.14
35	A"	1501	1465	7.70
36	A"	1430	1396	7.02
37	A"	1352	1320	3.35
38	A"	1130	1103	5.74
39	A"	1079	1053	0.00
40	A"	972	949	0.00
41	A"	927	905	0.22
42	A"	790	771	56.19
43	A"	728	710	0.09
44	A"	545	532	7.87
45	A"	256	250	0.10
46	A"	193	188	0.49
47	A"	158	154	0.14
48	A"	13	13	0.11

Unscaled Zero Point Vibrational Energy (zpe) 35804.1 cm^-1
Scaled (by 0.976) Zero Point Vibrational Energy (zpe) 34944.8 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-121G

A	B	C
0.14202	0.08028	0.07936

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

Geometric Data calculated at MP2/CEP-121G

Point Group is C_s

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.974	-1.859	0.000
C2	-0.064	-0.831	0.000
C3	-0.532	0.641	0.000
C4	1.451	-1.102	0.000
C5	-0.064	1.401	1.289
C6	-0.064	1.401	-1.289
H7	-0.658	-2.908	0.000
H8	-2.052	-1.666	0.000
H9	-1.640	0.622	0.000
H10	1.648	-2.187	0.000
H11	1.938	-0.665	-0.891
H12	1.938	-0.665	0.891
H13	-0.528	2.403	1.331
H14	-0.353	0.842	2.196
H15	1.033	1.534	1.294
H16	-0.528	2.403	-1.331
H17	-0.353	0.842	-2.196
H18	1.033	1.534	-1.294

Atom - Atom Distances (Å)

	C1	C2	C3	C4	C5	C6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17	H18
C1		1.3737	2.5392	2.5411	3.6225	3.6225	1.0950	1.0952	2.5695	2.6427	3.2710	3.2710	4.4876	3.5367	4.1498	4.4876	3.5367	4.1498
C2	1.3737		1.5445	1.5390	2.5775	2.5775	2.1605	2.1570	2.1438	2.1838	2.1971	2.1971	3.5276	2.7758	2.9106	3.5276	2.7758	2.9106
C3	2.5392	1.5445		2.6402	1.5680	1.5680	3.5511	2.7632	1.1079	3.5705	2.9326	2.9326	2.2083	2.2124	2.2187	2.2083	2.2124	2.2187
C4	2.5411	1.5390	2.6402		3.1972	3.1972	2.7771	3.5488	3.5394	1.1026	1.1048	1.1048	4.2392	3.4432	2.9663	4.2392	3.4432	2.9663
C5	3.6225	2.5775	1.5680	3.1972		2.5775	4.5370	3.8764	2.1799	4.1792	3.6093	2.9045	1.1046	1.1040	1.1046	2.8429	3.5409	2.8094
C6	3.6225	2.5775	1.5680	3.1972	2.5775		4.5370	3.8764	2.1799	4.1792	2.9045	3.6093	2.8429	3.5409	2.8094	1.1046	1.1040	1.1046
H7	1.0950	2.1605	3.5511	2.7771	4.5370	4.5370		1.8667	3.6641	2.4166	3.5444	3.5444	5.4766	4.3566	4.9263	5.4766	4.3566	4.9263
H8	1.0952	2.1570	2.7632	3.5488	3.8764	3.8764	1.8667		2.3257	3.7368	4.2092	4.2092	4.5448	3.7423	4.6301	4.5448	3.7423	4.6301
H9	2.5695	2.1438	1.1079	3.5394	2.1799	2.1799	3.6641	2.3257		4.3245	3.9053	3.9053	2.4857	2.5548	3.1065	2.4857	2.5548	3.1065
H10	2.6427	2.1838	3.5705	1.1026	4.1792	4.1792	2.4166	3.7368	4.3245		1.7866	1.7866	5.2508	4.2427	3.9874	5.2508	4.2427	3.9874
H11	3.2710	2.1971	2.9326	1.1048	3.6093	2.9045	3.5444	4.2092	3.9053	1.7866		1.7812	4.5199	4.1287	3.2297	3.9607	3.0370	2.4124
H12	3.2710	2.1971	2.9326	1.1048	2.9045	3.6093	3.5444	4.2092	3.9053	1.7866	1.7812		3.9607	3.0370	2.4124	4.5199	4.1287	3.2297
H13	4.4876	3.5276	2.2083	4.2392	1.1046	2.8429	5.4766	4.5448	2.4857	5.2508	4.5199	3.9607		1.7926	1.7865	2.6623	3.8608	3.1754
H14	3.5367	2.7758	2.2124	3.4432	1.1040	3.5409	4.3566	3.7423	2.5548	4.2427	4.1287	3.0370	1.7926		1.7920	3.8608	4.3917	3.8184
H15	4.1498	2.9106	2.2187	2.9663	1.1046	2.8094	4.9263	4.6301	3.1065	3.9874	3.2297	2.4124	1.7865	1.7920		3.1754	3.8184	2.5887
H16	4.4876	3.5276	2.2083	4.2392	2.8429	1.1046	5.4766	4.5448	2.4857	5.2508	3.9607	4.5199	2.6623	3.8608	3.1754		1.7926	1.7865
H17	3.5367	2.7758	2.2124	3.4432	3.5409	1.1040	4.3566	3.7423	2.5548	4.2427	3.0370	4.1287	3.8608	4.3917	3.8184	1.7926		1.7920
H18	4.1498	2.9106	2.2187	2.9663	2.8094	1.1046	4.9263	4.6301	3.1065	3.9874	2.4124	3.2297	3.1754	3.8184	2.5887	1.7865	1.7920

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	120.834	C1	C2	C4	121.375
C2	C1	H7	121.719	C2	C1	H8	121.365
C2	C3	C5	111.813	C2	C3	C6	111.813
C2	C3	H9	106.691	C2	C4	H10	110.423
C2	C4	H11	111.349	C2	C4	H12	111.349
C3	C2	C4	117.791	C3	C5	H13	110.231
C3	C5	H14	110.586	C3	C5	H15	111.041
C3	C6	H16	110.231	C3	C6	H17	110.586
C3	C6	H18	111.041	C5	C3	C6	110.555
C5	C3	H9	107.866	C6	C3	H9	107.866
H7	C1	H8	116.916	H10	C4	H11	108.066
H10	C4	H12	108.066	H11	C4	H12	107.443
H13	C5	H14	108.514	H13	C5	H15	107.928
H14	C5	H15	108.454	H16	C6	H17	108.514
H16	C6	H18	107.928	H17	C6	H18	108.454

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-121G

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-121G

States and conformations

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