CCCBDB calculation results Page

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

Energy calculated at MP2/6-31G(2df,p)

	hartrees
Energy at 0K	-235.182860
Energy at 298.15K	-235.195195
HF Energy	-234.206867
Nuclear repulsion energy	244.433325

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 MP2/6-31G(2df,p)

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3295	3113	10.36
2	A'	3202	3024	22.26
3	A'	3200	3023	1.89
4	A'	3196	3019	12.81
5	A'	3190	3013	41.14
6	A'	3100	2928	15.15
7	A'	3098	2926	9.56
8	A'	3096	2924	12.45
9	A'	1714	1619	6.97
10	A'	1541	1455	4.78
11	A'	1535	1449	8.64
12	A'	1520	1436	9.78
13	A'	1472	1390	1.52
14	A'	1433	1353	3.79
15	A'	1424	1345	6.79
16	A'	1354	1279	2.49
17	A'	1329	1255	0.41
18	A'	1205	1138	2.02
19	A'	1121	1059	11.33
20	A'	1014	958	1.62
21	A'	992	937	0.67
22	A'	924	872	1.57
23	A'	749	708	1.23
24	A'	520	491	1.19
25	A'	439	414	0.80
26	A'	328	310	0.24
27	A'	285	269	0.18
28	A'	269	254	0.28
29	A"	3196	3018	7.00
30	A"	3188	3011	3.41
31	A"	3176	3000	12.98
32	A"	3097	2925	16.78
33	A"	1529	1444	0.36
34	A"	1515	1431	0.89
35	A"	1504	1421	7.65
36	A"	1410	1331	5.43
37	A"	1355	1280	1.89
38	A"	1150	1086	1.86
39	A"	1075	1015	0.14
40	A"	982	927	0.26
41	A"	936	884	13.89
42	A"	930	878	21.34
43	A"	755	713	0.47
44	A"	549	518	5.95
45	A"	277	261	0.01
46	A"	211	199	0.30
47	A"	174	164	0.17
48	A"	29	27	0.09

Unscaled Zero Point Vibrational Energy (zpe) 36789.6 cm^-1
Scaled (by 0.9445) Zero Point Vibrational Energy (zpe) 34747.8 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 MP2/6-31G(2df,p)

A	B	C
0.14850	0.08401	0.08300

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

Geometric Data calculated at MP2/6-31G(2df,p)

Point Group is C_s

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-1.752	-1.064	0.000
C2	-0.476	-0.661	0.000
C3	-0.126	0.808	0.000
C4	0.655	-1.654	0.000
C5	0.655	1.202	1.257
C6	0.655	1.202	-1.257
H7	-2.016	-2.115	0.000
H8	-2.568	-0.351	0.000
H9	-1.070	1.364	0.000
H10	0.274	-2.676	0.000
H11	1.293	-1.532	-0.878
H12	1.293	-1.532	0.878
H13	0.812	2.283	1.285
H14	0.117	0.912	2.162
H15	1.638	0.727	1.277
H16	0.812	2.283	-1.285
H17	0.117	0.912	-2.162
H18	1.638	0.727	-1.277

Atom - Atom Distances (Å)

	C1	C2	C3	C4	C5	C6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17	H18
C1		1.3381	2.4792	2.4780	3.5368	3.5368	1.0835	1.0835	2.5217	2.5890	3.2039	3.2039	4.4077	3.4741	4.0407	4.4077	3.4741	4.0407
C2	1.3381		1.5102	1.5048	2.5164	2.5164	2.1176	2.1152	2.1104	2.1498	2.1588	2.1588	3.4610	2.7385	2.8329	3.4610	2.7385	2.8329
C3	2.4792	1.5102		2.5831	1.5319	1.5319	3.4803	2.7032	1.0953	3.5070	2.8747	2.8747	2.1698	2.1779	2.1793	2.1698	2.1779	2.1793
C4	2.4780	1.5048	2.5831		3.1211	3.1211	2.7100	3.4763	3.4762	1.0905	1.0926	1.0926	4.1446	3.3981	2.8753	4.1446	3.3981	2.8753
C5	3.5368	2.5164	1.5319	3.1211		2.5148	4.4404	3.7925	2.1406	4.0950	3.5281	2.8339	1.0923	1.0916	1.0920	2.7671	3.4734	2.7598
C6	3.5368	2.5164	1.5319	3.1211	2.5148		4.4404	3.7925	2.1406	4.0950	2.8339	3.5281	2.7671	3.4734	2.7598	1.0923	1.0916	1.0920
H7	1.0835	2.1176	3.4803	2.7100	4.4404	4.4404		1.8478	3.6049	2.3576	3.4730	3.4730	5.3842	4.2875	4.8015	5.3842	4.2875	4.8015
H8	1.0835	2.1152	2.7032	3.4763	3.7925	3.7925	1.8478		2.2774	3.6717	4.1326	4.1326	4.4743	3.6714	4.5258	4.4743	3.6714	4.5258
H9	2.5217	2.1104	1.0953	3.4762	2.1406	2.1406	3.6049	2.2774		4.2576	3.8400	3.8400	2.4576	2.5073	3.0608	2.4576	2.5073	3.0608
H10	2.5890	2.1498	3.5070	1.0905	4.0950	4.0950	2.3576	3.6717	4.2576		1.7660	1.7660	5.1510	4.1918	3.8822	5.1510	4.1918	3.8822
H11	3.2039	2.1588	2.8747	1.0926	3.5281	2.8339	3.4730	4.1326	3.8400	1.7660		1.7562	4.4122	4.0742	3.1414	3.8669	3.0010	2.3200
H12	3.2039	2.1588	2.8747	1.0926	2.8339	3.5281	3.4730	4.1326	3.8400	1.7660	1.7562		3.8669	3.0010	2.3200	4.4122	4.0742	3.1414
H13	4.4077	3.4610	2.1698	4.1446	1.0923	2.7671	5.3842	4.4743	2.4576	5.1510	4.4122	3.8669		1.7698	1.7612	2.5702	3.7742	3.1093
H14	3.4741	2.7385	2.1779	3.3981	1.0916	3.4734	4.2875	3.6714	2.5073	4.1918	4.0742	3.0010	1.7698		1.7689	3.7742	4.3236	3.7648
H15	4.0407	2.8329	2.1793	2.8753	1.0920	2.7598	4.8015	4.5258	3.0608	3.8822	3.1414	2.3200	1.7612	1.7689		3.1093	3.7648	2.5545
H16	4.4077	3.4610	2.1698	4.1446	2.7671	1.0923	5.3842	4.4743	2.4576	5.1510	3.8669	4.4122	2.5702	3.7742	3.1093		1.7698	1.7612
H17	3.4741	2.7385	2.1779	3.3981	3.4734	1.0916	4.2875	3.6714	2.5073	4.1918	3.0010	4.0742	3.7742	4.3236	3.7648	1.7698		1.7689
H18	4.0407	2.8329	2.1793	2.8753	2.7598	1.0920	4.8015	4.5258	3.0608	3.8822	2.3200	3.1414	3.1093	3.7648	2.5545	1.7612	1.7689

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	120.899	C1	C2	C4	121.192
C2	C1	H7	121.617	C2	C1	H8	121.370
C2	C3	C5	111.623	C2	C3	C6	111.623
C2	C3	H9	107.113	C2	C4	H10	110.852
C2	C4	H11	111.443	C2	C4	H12	111.443
C3	C2	C4	117.909	C3	C5	H13	110.432
C3	C5	H14	111.119	C3	C5	H15	111.206
C3	C6	H16	110.432	C3	C6	H17	111.119
C3	C6	H18	111.206	C5	C3	C6	110.334
C5	C3	H9	107.978	C6	C3	H9	107.978
H7	C1	H8	117.013	H10	C4	H11	107.979
H10	C4	H12	107.979	H11	C4	H12	106.961
H13	C5	H14	108.266	H13	C5	H15	107.477
H14	C5	H15	108.209	H16	C6	H17	108.266
H16	C6	H18	107.477	H17	C6	H18	108.209

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability

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

using model chemistry: MP2/6-31G(2df,p)

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: MP2/6-31G(2df,p)

States and conformations

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