CCCBDB calculation results Page

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

Energy calculated at MP2/3-21G

	hartrees
Energy at 0K	-233.434132
Energy at 298.15K	-233.446536
HF Energy	-232.882340
Nuclear repulsion energy	242.107671

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 MP2/3-21G

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3243	3095	19.00
2	A'	3162	3018	47.14
3	A'	3160	3016	3.39
4	A'	3152	3008	9.02
5	A'	3150	3006	53.09
6	A'	3081	2941	14.16
7	A'	3076	2936	9.78
8	A'	3067	2927	14.25
9	A'	1697	1619	3.89
10	A'	1609	1536	6.46
11	A'	1607	1534	9.18
12	A'	1596	1524	7.67
13	A'	1528	1458	0.22
14	A'	1496	1428	5.55
15	A'	1483	1416	8.15
16	A'	1394	1331	2.68
17	A'	1324	1264	0.56
18	A'	1241	1185	2.89
19	A'	1160	1107	13.48
20	A'	1063	1015	1.58
21	A'	974	929	0.34
22	A'	894	854	1.34
23	A'	719	686	0.96
24	A'	527	503	1.70
25	A'	454	434	0.36
26	A'	337	322	0.30
27	A'	288	275	0.20
28	A'	265	253	0.16
29	A"	3158	3015	4.15
30	A"	3149	3005	18.90
31	A"	3142	2999	13.23
32	A"	3076	2936	17.66
33	A"	1602	1529	0.33
34	A"	1590	1518	0.74
35	A"	1582	1510	8.55
36	A"	1473	1406	5.41
37	A"	1401	1337	1.57
38	A"	1157	1105	1.94
39	A"	1120	1069	2.23
40	A"	1001	956	0.66
41	A"	974	930	1.13
42	A"	935	892	45.28
43	A"	758	723	0.68
44	A"	559	533	8.04
45	A"	279	266	0.07
46	A"	221	211	0.56
47	A"	162	155	0.26
48	A"	27	26	0.06

Unscaled Zero Point Vibrational Energy (zpe) 37055.6 cm^-1
Scaled (by 0.9545) Zero Point Vibrational Energy (zpe) 35369.6 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 MP2/3-21G

A	B	C
0.14520	0.08225	0.08137

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

Geometric Data calculated at MP2/3-21G

Point Group is C_s

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-1.769	-1.074	0.000
C2	-0.486	-0.668	0.000
C3	-0.127	0.820	0.000
C4	0.665	-1.671	0.000
C5	0.665	1.214	1.276
C6	0.665	1.214	-1.276
H7	-2.038	-2.128	0.000
H8	-2.593	-0.364	0.000
H9	-1.073	1.381	0.000
H10	0.273	-2.694	0.000
H11	1.297	-1.545	-0.887
H12	1.297	-1.545	0.887
H13	0.834	2.297	1.294
H14	0.107	0.929	2.175
H15	1.639	0.714	1.292
H16	0.834	2.297	-1.294
H17	0.107	0.929	-2.175
H18	1.639	0.714	-1.292

Atom - Atom Distances (Å)

	C1	C2	C3	C4	C5	C6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17	H18
C1		1.3457	2.5070	2.5065	3.5764	3.5764	1.0874	1.0875	2.5517	2.6063	3.2262	3.2262	4.4517	3.5018	4.0601	4.4517	3.5018	4.0601
C2	1.3457		1.5304	1.5273	2.5487	2.5487	2.1306	2.1282	2.1306	2.1638	2.1763	2.1763	3.4941	2.7626	2.8455	3.4941	2.7626	2.8455
C3	2.5070	1.5304		2.6137	1.5528	1.5528	3.5131	2.7355	1.0998	3.5365	2.8994	2.8994	2.1864	2.1900	2.1909	2.1864	2.1900	2.1909
C4	2.5065	1.5273	2.6137		3.1546	3.1546	2.7415	3.5103	3.5118	1.0958	1.0961	1.0961	4.1774	3.4356	2.8819	4.1774	3.4356	2.8819
C5	3.5764	2.5487	1.5528	3.1546		2.5525	4.4837	3.8384	2.1627	4.1298	3.5625	2.8571	1.0965	1.0956	1.0953	2.7946	3.5075	2.7921
C6	3.5764	2.5487	1.5528	3.1546	2.5525		4.4837	3.8384	2.1627	4.1298	2.8571	3.5625	2.7946	3.5075	2.7921	1.0965	1.0956	1.0953
H7	1.0874	2.1306	3.5131	2.7415	4.4837	4.4837		1.8490	3.6388	2.3789	3.4995	3.4995	5.4317	4.3216	4.8236	5.4317	4.3216	4.8236
H8	1.0875	2.1282	2.7355	3.5103	3.8384	3.8384	1.8490		2.3139	3.6931	4.1605	4.1605	4.5276	3.7000	4.5544	4.5276	3.7000	4.5544
H9	2.5517	2.1306	1.0998	3.5118	2.1627	2.1627	3.6388	2.3139		4.2910	3.8680	3.8680	2.4800	2.5149	3.0774	2.4800	2.5149	3.0774
H10	2.6063	2.1638	3.5365	1.0958	4.1298	4.1298	2.3789	3.6931	4.2910		1.7764	1.7764	5.1868	4.2292	3.8923	5.1868	4.2292	3.8923
H11	3.2262	2.1763	2.8994	1.0961	3.5625	2.8571	3.4995	4.1605	3.8680	1.7764		1.7741	4.4426	4.1127	3.1573	3.8916	3.0328	2.3203
H12	3.2262	2.1763	2.8994	1.0961	2.8571	3.5625	3.4995	4.1605	3.8680	1.7764	1.7741		3.8916	3.0328	2.3203	4.4426	4.1127	3.1573
H13	4.4517	3.4941	2.1864	4.1774	1.0965	2.7946	5.4317	4.5276	2.4800	5.1868	4.4426	3.8916		1.7819	1.7768	2.5886	3.7993	3.1379
H14	3.5018	2.7626	2.1900	3.4356	1.0956	3.5075	4.3216	3.7000	2.5149	4.2292	4.1127	3.0328	1.7819		1.7818	3.7993	4.3496	3.7968
H15	4.0601	2.8455	2.1909	2.8819	1.0953	2.7921	4.8236	4.5544	3.0774	3.8923	3.1573	2.3203	1.7768	1.7818		3.1379	3.7968	2.5843
H16	4.4517	3.4941	2.1864	4.1774	2.7946	1.0965	5.4317	4.5276	2.4800	5.1868	3.8916	4.4426	2.5886	3.7993	3.1379		1.7819	1.7768
H17	3.5018	2.7626	2.1900	3.4356	3.5075	1.0956	4.3216	3.7000	2.5149	4.2292	3.0328	4.1127	3.7993	4.3496	3.7968	1.7819		1.7818
H18	4.0601	2.8455	2.1909	2.8819	2.7921	1.0953	4.8236	4.5544	3.0774	3.8923	2.3203	3.1573	3.1379	3.7968	2.5843	1.7768	1.7818

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	121.173	C1	C2	C4	121.356
C2	C1	H7	121.892	C2	C1	H8	121.647
C2	C3	C5	111.502	C2	C3	C6	111.502
C2	C3	H9	107.065	C2	C4	H10	110.067
C2	C4	H11	111.039	C2	C4	H12	111.039
C3	C2	C4	117.471	C3	C5	H13	110.039
C3	C5	H14	110.376	C3	C5	H15	110.463
C3	C6	H16	110.039	C3	C6	H17	110.376
C3	C6	H18	110.463	C5	C3	C6	110.549
C5	C3	H9	108.017	C6	C3	H9	108.017
H7	C1	H8	116.461	H10	C4	H11	108.274
H10	C4	H12	108.274	H11	C4	H12	108.050
H13	C5	H14	108.756	H13	C5	H15	108.319
H14	C5	H15	108.836	H16	C6	H17	108.756
H16	C6	H18	108.319	H17	C6	H18	108.836

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability

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

using model chemistry: MP2/3-21G

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: MP2/3-21G

States and conformations

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