CCCBDB calculation results Page

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

Energy calculated at MP2=FULL/3-21G

	hartrees
Energy at 0K	-233.444227
Energy at 298.15K	-233.456635
HF Energy	-232.882403
Nuclear repulsion energy	242.162362

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=FULL/3-21G

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3243	3097	18.93
2	A'	3163	3020	46.81
3	A'	3160	3018	3.46
4	A'	3152	3010	9.11
5	A'	3150	3008	52.72
6	A'	3081	2942	14.14
7	A'	3077	2937	9.73
8	A'	3067	2928	14.22
9	A'	1697	1621	3.91
10	A'	1609	1536	6.51
11	A'	1607	1535	9.18
12	A'	1596	1524	7.72
13	A'	1528	1459	0.22
14	A'	1496	1428	5.60
15	A'	1484	1417	8.20
16	A'	1395	1332	2.66
17	A'	1325	1265	0.56
18	A'	1241	1185	2.88
19	A'	1160	1108	13.50
20	A'	1063	1015	1.59
21	A'	974	930	0.35
22	A'	895	854	1.35
23	A'	719	687	0.96
24	A'	527	503	1.70
25	A'	455	434	0.36
26	A'	337	322	0.30
27	A'	288	275	0.20
28	A'	265	253	0.16
29	A"	3159	3016	4.13
30	A"	3149	3007	18.74
31	A"	3142	3000	13.24
32	A"	3077	2937	17.61
33	A"	1602	1530	0.33
34	A"	1590	1518	0.74
35	A"	1582	1510	8.61
36	A"	1474	1407	5.46
37	A"	1401	1338	1.56
38	A"	1158	1105	1.93
39	A"	1120	1070	2.25
40	A"	1002	956	0.66
41	A"	974	930	1.16
42	A"	936	894	45.22
43	A"	758	724	0.68
44	A"	559	534	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) 37063.5 cm^-1
Scaled (by 0.9548) Zero Point Vibrational Energy (zpe) 35388.2 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=FULL/3-21G

A	B	C
0.14527	0.08229	0.08142

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

Geometric Data calculated at MP2=FULL/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	-0.667	0.000
C3	-0.127	0.820	0.000
C4	0.665	-1.670	0.000
C5	0.665	1.214	1.276
C6	0.665	1.214	-1.276
H7	-2.038	-2.127	0.000
H8	-2.592	-0.364	0.000
H9	-1.073	1.381	0.000
H10	0.273	-2.693	0.000
H11	1.296	-1.544	-0.887
H12	1.296	-1.544	0.887
H13	0.834	2.297	1.294
H14	0.107	0.929	2.174
H15	1.639	0.713	1.292
H16	0.834	2.297	-1.294
H17	0.107	0.929	-2.174
H18	1.639	0.713	-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		1.3454	2.5064	2.5059	3.5756	3.5756	1.0873	1.0874	2.5513	2.6059	3.2256	3.2256	4.4508	3.5012	4.0592	4.4508	3.5012	4.0592
C2	1.3454		1.5300	1.5269	2.5479	2.5479	2.1303	2.1278	2.1303	2.1635	2.1759	2.1759	3.4934	2.7621	2.8447	3.4934	2.7621	2.8447
C3	2.5064	1.5300		2.6130	1.5525	1.5525	3.5124	2.7350	1.0996	3.5358	2.8987	2.8987	2.1861	2.1897	2.1905	2.1861	2.1897	2.1905
C4	2.5059	1.5269	2.6130		3.1536	3.1536	2.7410	3.5097	3.5111	1.0957	1.0960	1.0960	4.1762	3.4347	2.8808	4.1762	3.4347	2.8808
C5	3.5756	2.5479	1.5525	3.1536		2.5518	4.4827	3.8377	2.1623	4.1287	3.5615	2.8562	1.0963	1.0955	1.0951	2.7939	3.5068	2.7913
C6	3.5756	2.5479	1.5525	3.1536	2.5518		4.4827	3.8377	2.1623	4.1287	2.8562	3.5615	2.7939	3.5068	2.7913	1.0963	1.0955	1.0951
H7	1.0873	2.1303	3.5124	2.7410	4.4827	4.4827		1.8488	3.6383	2.3786	3.4989	3.4989	5.4307	4.3208	4.8225	5.4307	4.3208	4.8225
H8	1.0874	2.1278	2.7350	3.5097	3.8377	3.8377	1.8488		2.3136	3.6926	4.1598	4.1598	4.5269	3.6995	4.5535	4.5269	3.6995	4.5535
H9	2.5513	2.1303	1.0996	3.5111	2.1623	2.1623	3.6383	2.3136		4.2903	3.8673	3.8673	2.4797	2.5146	3.0769	2.4797	2.5146	3.0769
H10	2.6059	2.1635	3.5358	1.0957	4.1287	4.1287	2.3786	3.6926	4.2903		1.7761	1.7761	5.1856	4.2283	3.8911	5.1856	4.2283	3.8911
H11	3.2256	2.1759	2.8987	1.0960	3.5615	2.8562	3.4989	4.1598	3.8673	1.7761		1.7738	4.4414	4.1117	3.1562	3.8904	3.0319	2.3193
H12	3.2256	2.1759	2.8987	1.0960	2.8562	3.5615	3.4989	4.1598	3.8673	1.7761	1.7738		3.8904	3.0319	2.3193	4.4414	4.1117	3.1562
H13	4.4508	3.4934	2.1861	4.1762	1.0963	2.7939	5.4307	4.5269	2.4797	5.1856	4.4414	3.8904		1.7816	1.7764	2.5881	3.7986	3.1371
H14	3.5012	2.7621	2.1897	3.4347	1.0955	3.5068	4.3208	3.6995	2.5146	4.2283	4.1117	3.0319	1.7816		1.7815	3.7986	4.3489	3.7959
H15	4.0592	2.8447	2.1905	2.8808	1.0951	2.7913	4.8225	4.5535	3.0769	3.8911	3.1562	2.3193	1.7764	1.7815		3.1371	3.7959	2.5834
H16	4.4508	3.4934	2.1861	4.1762	2.7939	1.0963	5.4307	4.5269	2.4797	5.1856	3.8904	4.4414	2.5881	3.7986	3.1371		1.7816	1.7764
H17	3.5012	2.7621	2.1897	3.4347	3.5068	1.0955	4.3208	3.6995	2.5146	4.2283	3.0319	4.1117	3.7986	4.3489	3.7959	1.7816		1.7815
H18	4.0592	2.8447	2.1905	2.8808	2.7913	1.0951	4.8225	4.5535	3.0769	3.8911	2.3193	3.1562	3.1371	3.7959	2.5834	1.7764	1.7815

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	121.176	C1	C2	C4	121.357
C2	C1	H7	121.894	C2	C1	H8	121.651
C2	C3	C5	111.498	C2	C3	C6	111.498
C2	C3	H9	107.073	C2	C4	H10	110.076
C2	C4	H11	111.044	C2	C4	H12	111.044
C3	C2	C4	117.467	C3	C5	H13	110.046
C3	C5	H14	110.384	C3	C5	H15	110.464
C3	C6	H16	110.046	C3	C6	H17	110.384
C3	C6	H18	110.464	C5	C3	C6	110.542
C5	C3	H9	108.021	C6	C3	H9	108.021
H7	C1	H8	116.456	H10	C4	H11	108.267
H10	C4	H12	108.267	H11	C4	H12	108.042
H13	C5	H14	108.752	H13	C5	H15	108.311
H14	C5	H15	108.831	H16	C6	H17	108.752
H16	C6	H18	108.311	H17	C6	H18	108.831

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=FULL/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=FULL/3-21G

States and conformations

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