CCCBDB calculation results Page

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

Energy calculated at CISD/3-21G*

	hartrees
Energy at 0K	-233.395740
Energy at 298.15K	-233.408258
HF Energy	-232.883916
Nuclear repulsion energy	243.021338

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 CISD/3-21G*

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3291	3075	19.86
2	A'	3218	3007	10.34
3	A'	3200	2990	41.22
4	A'	3193	2983	13.53
5	A'	3188	2979	60.59
6	A'	3132	2926	8.61
7	A'	3125	2920	20.04
8	A'	3122	2918	9.05
9	A'	1786	1669	8.56
10	A'	1631	1524	6.20
11	A'	1629	1522	10.51
12	A'	1618	1512	9.18
13	A'	1562	1460	0.41
14	A'	1528	1428	6.42
15	A'	1517	1418	9.14
16	A'	1430	1336	3.16
17	A'	1363	1273	0.61
18	A'	1266	1183	3.31
19	A'	1188	1110	13.53
20	A'	1089	1018	1.42
21	A'	997	932	0.28
22	A'	914	854	1.19
23	A'	737	689	0.95
24	A'	539	503	1.69
25	A'	467	436	0.40
26	A'	345	323	0.28
27	A'	295	276	0.23
28	A'	266	249	0.15
29	A"	3195	2985	4.32
30	A"	3186	2977	22.53
31	A"	3178	2970	13.98
32	A"	3121	2916	19.64
33	A"	1624	1517	0.55
34	A"	1611	1506	0.97
35	A"	1604	1499	9.28
36	A"	1506	1407	6.72
37	A"	1429	1335	1.14
38	A"	1184	1106	1.36
39	A"	1143	1068	3.59
40	A"	1019	952	3.01
41	A"	1003	938	45.27
42	A"	994	929	1.94
43	A"	778	727	0.70
44	A"	580	542	8.99
45	A"	283	264	0.12
46	A"	225	210	0.58
47	A"	163	153	0.21
48	A"	25	23	0.07

Unscaled Zero Point Vibrational Energy (zpe) 37742.9 cm^-1
Scaled (by 0.9344) Zero Point Vibrational Energy (zpe) 35267.0 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 CISD/3-21G*

A	B	C
0.14631	0.08279	0.08199

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

Geometric Data calculated at CISD/3-21G*

Point Group is C_s

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-1.757	-1.070	0.000
C2	-0.488	-0.668	0.000
C3	-0.129	0.817	0.000
C4	0.662	-1.667	0.000
C5	0.662	1.211	1.272
C6	0.662	1.211	-1.272
H7	-2.026	-2.119	0.000
H8	-2.579	-0.366	0.000
H9	-1.068	1.377	0.000
H10	0.277	-2.687	0.000
H11	1.291	-1.539	-0.883
H12	1.291	-1.539	0.883
H13	0.824	2.291	1.293
H14	0.110	0.923	2.169
H15	1.636	0.720	1.288
H16	0.824	2.291	-1.293
H17	0.110	0.923	-2.169
H18	1.636	0.720	-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		1.3313	2.4928	2.4912	3.5598	3.5598	1.0826	1.0827	2.5422	2.5983	3.2079	3.2079	4.4308	3.4881	4.0467	4.4308	3.4881	4.0467
C2	1.3313		1.5279	1.5231	2.5435	2.5435	2.1146	2.1131	2.1255	2.1595	2.1690	2.1690	3.4853	2.7560	2.8452	3.4853	2.7560	2.8452
C3	2.4928	1.5279		2.6067	1.5487	1.5487	3.4959	2.7216	1.0939	3.5280	2.8892	2.8892	2.1799	2.1850	2.1868	2.1799	2.1850	2.1868
C4	2.4912	1.5231	2.6067		3.1461	3.1461	2.7257	3.4925	3.5011	1.0909	1.0921	1.0921	4.1665	3.4231	2.8812	4.1665	3.4231	2.8812
C5	3.5598	2.5435	1.5487	3.1461		2.5447	4.4643	3.8225	2.1542	4.1185	3.5501	2.8474	1.0923	1.0915	1.0913	2.7886	3.4974	2.7827
C6	3.5598	2.5435	1.5487	3.1461	2.5447		4.4643	3.8225	2.1542	4.1185	2.8474	3.5501	2.7886	3.4974	2.7827	1.0923	1.0915	1.0913
H7	1.0826	2.1146	3.4959	2.7257	4.4643	4.4643		1.8380	3.6246	2.3720	3.4815	3.4815	5.4076	4.3041	4.8092	5.4076	4.3041	4.8092
H8	1.0827	2.1131	2.7216	3.4925	3.8225	3.8225	1.8380		2.3068	3.6805	4.1397	4.1397	4.5075	3.6883	4.5398	4.5075	3.6883	4.5398
H9	2.5422	2.1255	1.0939	3.5011	2.1542	2.1542	3.6246	2.3068		4.2811	3.8536	3.8536	2.4680	2.5102	3.0669	2.4680	2.5102	3.0669
H10	2.5983	2.1595	3.5280	1.0909	4.1185	4.1185	2.3720	3.6805	4.2811		1.7687	1.7687	5.1724	4.2155	3.8876	5.1724	4.2155	3.8876
H11	3.2079	2.1690	2.8892	1.0921	3.5501	2.8474	3.4815	4.1397	3.8536	1.7687		1.7666	4.4296	4.0957	3.1516	3.8796	3.0183	2.3202
H12	3.2079	2.1690	2.8892	1.0921	2.8474	3.5501	3.4815	4.1397	3.8536	1.7687	1.7666		3.8796	3.0183	2.3202	4.4296	4.0957	3.1516
H13	4.4308	3.4853	2.1799	4.1665	1.0923	2.7886	5.4076	4.5075	2.4680	5.1724	4.4296	3.8796		1.7738	1.7685	2.5870	3.7908	3.1287
H14	3.4881	2.7560	2.1850	3.4231	1.0915	3.4974	4.3041	3.6883	2.5102	4.2155	4.0957	3.0183	1.7738		1.7741	3.7908	4.3386	3.7841
H15	4.0467	2.8452	2.1868	2.8812	1.0913	2.7827	4.8092	4.5398	3.0669	3.8876	3.1516	2.3202	1.7685	1.7741		3.1287	3.7841	2.5751
H16	4.4308	3.4853	2.1799	4.1665	2.7886	1.0923	5.4076	4.5075	2.4680	5.1724	3.8796	4.4296	2.5870	3.7908	3.1287		1.7738	1.7685
H17	3.4881	2.7560	2.1850	3.4231	3.4974	1.0915	4.3041	3.6883	2.5102	4.2155	3.0183	4.0957	3.7908	4.3386	3.7841	1.7738		1.7741
H18	4.0467	2.8452	2.1868	2.8812	2.7827	1.0913	4.8092	4.5398	3.0669	3.8876	2.3202	3.1516	3.1287	3.7841	2.5751	1.7685	1.7741

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	121.200	C1	C2	C4	121.421
C2	C1	H7	121.993	C2	C1	H8	121.840
C2	C3	C5	111.529	C2	C3	C6	111.529
C2	C3	H9	107.169	C2	C4	H10	110.311
C2	C4	H11	110.996	C2	C4	H12	110.996
C3	C2	C4	117.378	C3	C5	H13	110.060
C3	C5	H14	110.508	C3	C5	H15	110.664
C3	C6	H16	110.060	C3	C6	H17	110.508
C3	C6	H18	110.664	C5	C3	C6	110.479
C5	C3	H9	107.974	C6	C3	H9	107.974
H7	C1	H8	116.167	H10	C4	H11	108.234
H10	C4	H12	108.234	H11	C4	H12	107.966
H13	C5	H14	108.637	H13	C5	H15	108.169
H14	C5	H15	108.739	H16	C6	H17	108.637
H16	C6	H18	108.169	H17	C6	H18	108.739

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability

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

using model chemistry: CISD/3-21G*

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: CISD/3-21G*

States and conformations

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