CCCBDB calculation results Page

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

Energy calculated at MP2/CEP-31G

	hartrees
Energy at 0K	-40.279268
Energy at 298.15K	-40.291365
HF Energy	-39.783676
Nuclear repulsion energy	133.600510

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/CEP-31G

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3223	3115	40.84
2	A'	3133	3027	103.85
3	A'	3131	3026	2.86
4	A'	3127	3021	12.31
5	A'	3123	3018	152.21
6	A'	3050	2947	22.19
7	A'	3024	2922	48.74
8	A'	3019	2917	24.18
9	A'	1665	1609	7.67
10	A'	1538	1486	1.78
11	A'	1531	1480	16.14
12	A'	1525	1474	10.79
13	A'	1474	1425	1.57
14	A'	1455	1406	6.43
15	A'	1449	1400	6.80
16	A'	1363	1317	3.13
17	A'	1328	1284	0.48
18	A'	1214	1173	3.29
19	A'	1130	1092	13.67
20	A'	1021	987	1.53
21	A'	976	943	0.25
22	A'	901	871	1.09
23	A'	720	696	0.98
24	A'	517	500	1.19
25	A'	430	416	0.54
26	A'	325	314	0.27
27	A'	273	264	0.20
28	A'	247	239	0.06
29	A"	3124	3019	17.50
30	A"	3120	3015	19.00
31	A"	3109	3004	46.58
32	A"	3018	2917	46.65
33	A"	1528	1477	0.00
34	A"	1513	1462	2.77
35	A"	1505	1454	10.70
36	A"	1435	1386	6.22
37	A"	1365	1319	2.01
38	A"	1142	1104	5.87
39	A"	1081	1045	0.21
40	A"	982	949	0.00
41	A"	945	913	1.33
42	A"	834	806	76.58
43	A"	732	707	0.53
44	A"	540	521	8.54
45	A"	255	246	0.21
46	A"	202	195	0.54
47	A"	161	156	0.29
48	A"	8	8	0.04

Unscaled Zero Point Vibrational Energy (zpe) 36256.3 cm^-1
Scaled (by 0.9663) Zero Point Vibrational Energy (zpe) 35034.4 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/CEP-31G

A	B	C
0.14037	0.07915	0.07808

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

Geometric Data calculated at MP2/CEP-31G

Point Group is C_s

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-1.812	-1.095	0.000
C2	-0.483	-0.682	0.000
C3	-0.122	0.827	0.000
C4	0.675	-1.711	0.000
C5	0.675	1.243	1.293
C6	0.675	1.243	-1.293
H7	-2.084	-2.163	0.000
H8	-2.637	-0.364	0.000
H9	-1.087	1.386	0.000
H10	0.276	-2.746	0.000
H11	1.322	-1.590	-0.897
H12	1.322	-1.590	0.897
H13	0.807	2.348	1.322
H14	0.129	0.930	2.210
H15	1.685	0.777	1.309
H16	0.807	2.348	-1.322
H17	0.129	0.930	-2.210
H18	1.685	0.777	-1.309

Atom - Atom Distances (Å)

	C1	C2	C3	C4	C5	C6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17	H18
C1		1.3920	2.5594	2.5625	3.6508	3.6508	1.1018	1.1021	2.5851	2.6622	3.2971	3.2971	4.5236	3.5710	4.1770	4.5236	3.5710	4.1770
C2	1.3920		1.5518	1.5488	2.5927	2.5927	2.1809	2.1772	2.1549	2.1992	2.2101	2.2101	3.5487	2.8029	2.9227	3.5487	2.8029	2.9227
C3	2.5594	1.5518		2.6599	1.5754	1.5754	3.5760	2.7821	1.1151	3.5956	2.9548	2.9548	2.2191	2.2262	2.2317	2.2191	2.2262	2.2317
C4	2.5625	1.5488	2.6599		3.2246	3.2246	2.7964	3.5754	3.5631	1.1103	1.1121	1.1121	4.2702	3.4861	2.9868	4.2702	3.4861	2.9868
C5	3.6508	2.5927	1.5754	3.2246		2.5867	4.5705	3.9018	2.1906	4.2132	3.6390	2.9330	1.1126	1.1117	1.1121	2.8420	3.5591	2.8298
C6	3.6508	2.5927	1.5754	3.2246	2.5867		4.5705	3.9018	2.1906	4.2132	2.9330	3.6390	2.8420	3.5591	2.8298	1.1126	1.1117	1.1121
H7	1.1018	2.1809	3.5760	2.7964	4.5705	4.5705		1.8819	3.6864	2.4313	3.5684	3.5684	5.5185	4.3985	4.9561	5.5185	4.3985	4.9561
H8	1.1021	2.1772	2.7821	3.5754	3.9018	3.9018	1.8819		2.3375	3.7630	4.2399	4.2399	4.5784	3.7690	4.6572	4.5784	3.7690	4.6572
H9	2.5851	2.1549	1.1151	3.5631	2.1906	2.1906	3.6864	2.3375		4.3516	3.9324	3.9324	2.5022	2.5630	3.1251	2.5022	2.5630	3.1251
H10	2.6622	2.1992	3.5956	1.1103	4.2132	4.2132	2.4313	3.7630	4.3516		1.7988	1.7988	5.2897	4.2919	4.0144	5.2897	4.2919	4.0144
H11	3.2971	2.2101	2.9548	1.1121	3.6390	2.9330	3.5684	4.2399	3.9324	1.7988		1.7937	4.5489	4.1740	3.2559	3.9938	3.0815	2.4301
H12	3.2971	2.2101	2.9548	1.1121	2.9330	3.6390	3.5684	4.2399	3.9324	1.7988	1.7937		3.9938	3.0815	2.4301	4.5489	4.1740	3.2559
H13	4.5236	3.5487	2.2191	4.2702	1.1126	2.8420	5.5185	4.5784	2.5022	5.2897	4.5489	3.9938		1.8050	1.7989	2.6438	3.8654	3.1870
H14	3.5710	2.8029	2.2262	3.4861	1.1117	3.5591	4.3985	3.7690	2.5630	4.2919	4.1740	3.0815	1.8050		1.8041	3.8654	4.4192	3.8500
H15	4.1770	2.9227	2.2317	2.9868	1.1121	2.8298	4.9561	4.6572	3.1251	4.0144	3.2559	2.4301	1.7989	1.8041		3.1870	3.8500	2.6177
H16	4.5236	3.5487	2.2191	4.2702	2.8420	1.1126	5.5185	4.5784	2.5022	5.2897	3.9938	4.5489	2.6438	3.8654	3.1870		1.8050	1.7989
H17	3.5710	2.8029	2.2262	3.4861	3.5591	1.1117	4.3985	3.7690	2.5630	4.2919	3.0815	4.1740	3.8654	4.4192	3.8500	1.8050		1.8041
H18	4.1770	2.9227	2.2317	2.9868	2.8298	1.1121	4.9561	4.6572	3.1251	4.0144	2.4301	3.2559	3.1870	3.8500	2.6177	1.7989	1.8041

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	120.690	C1	C2	C4	121.151
C2	C1	H7	121.547	C2	C1	H8	121.173
C2	C3	C5	112.006	C2	C3	C6	112.006
C2	C3	H9	106.659	C2	C4	H10	110.512
C2	C4	H11	111.264	C2	C4	H12	111.264
C3	C2	C4	118.159	C3	C5	H13	110.094
C3	C5	H14	110.699	C3	C5	H15	111.110
C3	C6	H16	110.094	C3	C6	H17	110.699
C3	C6	H18	111.110	C5	C3	C6	110.360
C5	C3	H9	107.780	C6	C3	H9	107.780
H7	C1	H8	117.280	H10	C4	H11	108.078
H10	C4	H12	108.078	H11	C4	H12	107.505
H13	C5	H14	108.481	H13	C5	H15	107.923
H14	C5	H15	108.443	H16	C6	H17	108.481
H16	C6	H18	107.923	H17	C6	H18	108.443

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/CEP-31G

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/CEP-31G

States and conformations

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