CCCBDB calculation results Page

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

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

	hartrees
Energy at 0K	-235.254100
Energy at 298.15K	-235.266452
HF Energy	-234.207006
Nuclear repulsion energy	243.758468

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

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3267	3095	14.53
2	A'	3183	3016	7.13
3	A'	3170	3003	20.13
4	A'	3162	2995	25.94
5	A'	3156	2990	56.53
6	A'	3083	2921	10.80
7	A'	3079	2917	21.69
8	A'	3078	2916	8.96
9	A'	1740	1648	10.27
10	A'	1544	1463	3.34
11	A'	1538	1457	8.16
12	A'	1526	1446	8.82
13	A'	1483	1405	1.67
14	A'	1449	1373	2.94
15	A'	1440	1365	5.42
16	A'	1369	1297	3.48
17	A'	1339	1268	0.41
18	A'	1213	1149	2.06
19	A'	1130	1070	9.19
20	A'	1023	969	1.26
21	A'	993	940	0.53
22	A'	921	873	1.15
23	A'	745	706	0.93
24	A'	523	496	0.94
25	A'	443	420	0.95
26	A'	331	314	0.18
27	A'	284	269	0.24
28	A'	264	250	0.19
29	A"	3160	2993	8.97
30	A"	3153	2987	6.32
31	A"	3142	2977	18.29
32	A"	3076	2915	19.38
33	A"	1533	1452	0.39
34	A"	1519	1439	0.74
35	A"	1511	1431	6.51
36	A"	1427	1352	4.55
37	A"	1371	1299	1.96
38	A"	1153	1092	2.17
39	A"	1081	1024	0.14
40	A"	984	932	0.11
41	A"	944	894	26.96
42	A"	938	888	7.60
43	A"	754	714	0.47
44	A"	554	525	5.57
45	A"	273	259	0.01
46	A"	212	201	0.25
47	A"	172	163	0.11
48	A"	31	29	0.09

Unscaled Zero Point Vibrational Energy (zpe) 36730.0 cm^-1
Scaled (by 0.9474) Zero Point Vibrational Energy (zpe) 34798.0 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 QCISD/6-31G(2df,p)

A	B	C
0.14778	0.08335	0.08241

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

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

Point Group is C_s

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.948	-1.820	0.000
C2	-0.065	-0.818	0.000
C3	-0.525	0.629	0.000
C4	1.422	-1.086	0.000
C5	-0.065	1.374	1.261
C6	-0.065	1.374	-1.261
H7	-0.634	-2.858	0.000
H8	-2.017	-1.635	0.000
H9	-1.620	0.616	0.000
H10	1.623	-2.159	0.000
H11	1.906	-0.651	-0.879
H12	1.906	-0.651	0.879
H13	-0.491	2.381	1.286
H14	-0.378	0.848	2.167
H15	1.024	1.478	1.288
H16	-0.491	2.381	-1.286
H17	-0.378	0.848	-2.167
H18	1.024	1.478	-1.288

Atom - Atom Distances (Å)

	C1	C2	C3	C4	C5	C6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17	H18
C1		1.3360	2.4849	2.4809	3.5460	3.5460	1.0845	1.0845	2.5270	2.5935	3.2072	3.2072	4.4169	3.4837	4.0528	4.4169	3.4837	4.0528
C2	1.3360		1.5177	1.5103	2.5290	2.5290	2.1178	2.1162	2.1155	2.1555	2.1645	2.1645	3.4738	2.7508	2.8488	3.4738	2.7508	2.8488
C3	2.4849	1.5177		2.5937	1.5358	1.5358	3.4880	2.7110	1.0957	3.5187	2.8844	2.8844	2.1739	2.1826	2.1858	2.1739	2.1826	2.1858
C4	2.4809	1.5103	2.5937		3.1388	3.1388	2.7136	3.4820	3.4856	1.0915	1.0940	1.0940	4.1632	3.4167	2.8970	4.1632	3.4167	2.8970
C5	3.5460	2.5290	1.5358	3.1388		2.5230	4.4524	3.8021	2.1414	4.1135	3.5454	2.8518	1.0936	1.0931	1.0935	2.7725	3.4825	2.7741
C6	3.5460	2.5290	1.5358	3.1388	2.5230		4.4524	3.8021	2.1414	4.1135	2.8518	3.5454	2.7725	3.4825	2.7741	1.0936	1.0931	1.0935
H7	1.0845	2.1178	3.4880	2.7136	4.4524	4.4524		1.8463	3.6112	2.3625	3.4773	3.4773	5.3960	4.3001	4.8173	5.3960	4.3001	4.8173
H8	1.0845	2.1162	2.7110	3.4820	3.8021	3.8021	1.8463		2.2856	3.6774	4.1388	4.1388	4.4840	3.6800	4.5381	4.4840	3.6800	4.5381
H9	2.5270	2.1155	1.0957	3.4856	2.1414	2.1414	3.6112	2.2856		4.2682	3.8489	3.8489	2.4582	2.5080	3.0646	2.4582	2.5080	3.0646
H10	2.5935	2.1555	3.5187	1.0915	4.1135	4.1135	2.3625	3.6774	4.2682		1.7679	1.7679	5.1703	4.2118	3.9046	5.1703	4.2118	3.9046
H11	3.2072	2.1645	2.8844	1.0940	3.5454	2.8518	3.4773	4.1388	3.8489	1.7679		1.7587	4.4308	4.0920	3.1642	3.8868	3.0205	2.3412
H12	3.2072	2.1645	2.8844	1.0940	2.8518	3.5454	3.4773	4.1388	3.8489	1.7679	1.7587		3.8868	3.0205	2.3412	4.4308	4.0920	3.1642
H13	4.4169	3.4738	2.1739	4.1632	1.0936	2.7725	5.3960	4.4840	2.4582	5.1703	4.4308	3.8868		1.7714	1.7634	2.5727	3.7797	3.1205
H14	3.4837	2.7508	2.1826	3.4167	1.0931	3.4825	4.3001	3.6800	2.5080	4.2118	4.0920	3.0205	1.7714		1.7705	3.7797	4.3333	3.7813
H15	4.0528	2.8488	2.1858	2.8970	1.0935	2.7741	4.8173	4.5381	3.0646	3.9046	3.1642	2.3412	1.7634	1.7705		3.1205	3.7813	2.5763
H16	4.4169	3.4738	2.1739	4.1632	2.7725	1.0936	5.3960	4.4840	2.4582	5.1703	3.8868	4.4308	2.5727	3.7797	3.1205		1.7714	1.7634
H17	3.4837	2.7508	2.1826	3.4167	3.4825	1.0931	4.3001	3.6800	2.5080	4.2118	3.0205	4.0920	3.7797	4.3333	3.7813	1.7714		1.7705
H18	4.0528	2.8488	2.1858	2.8970	2.7741	1.0935	4.8173	4.5381	3.0646	3.9046	2.3412	3.1642	3.1205	3.7813	2.5763	1.7634	1.7705

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	120.961	C1	C2	C4	121.176
C2	C1	H7	121.735	C2	C1	H8	121.573
C2	C3	C5	111.833	C2	C3	C6	111.833
C2	C3	H9	106.985	C2	C4	H10	110.859
C2	C4	H11	111.427	C2	C4	H12	111.427
C3	C2	C4	117.862	C3	C5	H13	110.406
C3	C5	H14	111.132	C3	C5	H15	111.360
C3	C6	H16	110.406	C3	C6	H17	111.132
C3	C6	H18	111.360	C5	C3	C6	110.448
C5	C3	H9	107.755	C6	C3	H9	107.755
H7	C1	H8	116.693	H10	C4	H11	107.981
H10	C4	H12	107.981	H11	C4	H12	106.986
H13	C5	H14	108.208	H13	C5	H15	107.463
H14	C5	H15	108.134	H16	C6	H17	108.208
H16	C6	H18	107.463	H17	C6	H18	108.134

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability

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

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

States and conformations

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