CCCBDB calculation results Page

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

Energy calculated at MP2/CEP-121G*

	hartrees
Energy at 0K	-40.703921
Energy at 298.15K
HF Energy	-39.907661
Nuclear repulsion energy	136.306277

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-121G*

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3260	3106	21.96
2	A'	3165	3016	44.78
3	A'	3161	3012	1.41
4	A'	3158	3009	29.37
5	A'	3151	3002	78.00
6	A'	3071	2926	12.44
7	A'	3061	2916	32.52
8	A'	3055	2911	17.16
9	A'	1686	1606	10.05
10	A'	1546	1473	1.25
11	A'	1545	1472	16.62
12	A'	1530	1457	11.07
13	A'	1473	1404	1.67
14	A'	1452	1383	5.92
15	A'	1441	1373	7.21
16	A'	1360	1296	2.84
17	A'	1327	1264	0.41
18	A'	1211	1154	2.03
19	A'	1120	1067	8.50
20	A'	1015	967	0.99
21	A'	988	941	0.35
22	A'	920	876	1.13
23	A'	742	707	0.83
24	A'	522	497	0.85
25	A'	442	421	0.82
26	A'	332	317	0.15
27	A'	285	272	0.21
28	A'	262	250	0.25
29	A"	3157	3008	11.27
30	A"	3148	3000	11.39
31	A"	3139	2991	22.20
32	A"	3053	2909	29.49
33	A"	1537	1464	0.18
34	A"	1521	1449	4.17
35	A"	1513	1442	8.11
36	A"	1429	1361	8.01
37	A"	1361	1297	1.54
38	A"	1147	1092	4.19
39	A"	1073	1022	0.32
40	A"	979	933	0.09
41	A"	934	890	0.36
42	A"	831	791	55.39
43	A"	742	707	0.39
44	A"	547	521	8.33
45	A"	272	259	0.05
46	A"	200	190	0.55
47	A"	162	154	0.20
48	A"	22i	20i	0.12

Unscaled Zero Point Vibrational Energy (zpe) 36499.0 cm^-1
Scaled (by 0.9528) Zero Point Vibrational Energy (zpe) 34776.2 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/CEP-121G*

A	B	C
0.14625	0.08275	0.08171

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

Geometric Data calculated at MP2/CEP-121G*

Point Group is C_s

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-1.768	-1.070	0.000
C2	-0.477	-0.666	0.000
C3	-0.124	0.813	0.000
C4	0.660	-1.670	0.000
C5	0.660	1.212	1.267
C6	0.660	1.212	-1.267
H7	-2.037	-2.124	0.000
H8	-2.585	-0.351	0.000
H9	-1.071	1.372	0.000
H10	0.271	-2.693	0.000
H11	1.299	-1.549	-0.883
H12	1.299	-1.549	0.883
H13	0.795	2.300	1.304
H14	0.126	0.899	2.172
H15	1.656	0.754	1.278
H16	0.795	2.300	-1.304
H17	0.126	0.899	-2.172
H18	1.656	0.754	-1.278

Atom - Atom Distances (Å)

	C1	C2	C3	C4	C5	C6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17	H18
C1		1.3529	2.4998	2.5015	3.5648	3.5648	1.0882	1.0881	2.5390	2.6070	3.2272	3.2272	4.4297	3.4904	4.0848	4.4297	3.4904	4.0848
C2	1.3529		1.5209	1.5170	2.5348	2.5348	2.1355	2.1315	2.1225	2.1611	2.1706	2.1706	3.4806	2.7443	2.8636	3.4806	2.7443	2.8636
C3	2.4998	1.5209		2.6046	1.5426	1.5426	3.5055	2.7223	1.0991	3.5291	2.8955	2.8955	2.1806	2.1879	2.1922	2.1806	2.1879	2.1922
C4	2.5015	1.5170	2.6046		3.1486	3.1486	2.7352	3.5031	3.5000	1.0945	1.0965	1.0965	4.1812	3.4066	2.9162	4.1812	3.4066	2.9162
C5	3.5648	2.5348	1.5426	3.1486		2.5344	4.4733	3.8181	2.1511	4.1242	3.5571	2.8596	1.0968	1.0959	1.0962	2.7955	3.4942	2.7712
C6	3.5648	2.5348	1.5426	3.1486	2.5344		4.4733	3.8181	2.1511	4.1242	2.8596	3.5571	2.7955	3.4942	2.7712	1.0968	1.0959	1.0962
H7	1.0882	2.1355	3.5055	2.7352	4.4733	4.4733		1.8560	3.6268	2.3778	3.4984	3.4984	5.4121	4.3056	4.8537	5.4121	4.3056	4.8537
H8	1.0881	2.1315	2.7223	3.5031	3.8181	3.8181	1.8560		2.2933	3.6942	4.1591	4.1591	4.4886	3.6919	4.5651	4.4886	3.6919	4.5651
H9	2.5390	2.1225	1.0991	3.5000	2.1511	2.1511	3.6268	2.2933		4.2810	3.8631	3.8631	2.4582	2.5245	3.0741	2.4582	2.5245	3.0741
H10	2.6070	2.1611	3.5291	1.0945	4.1242	4.1242	2.3778	3.6942	4.2810		1.7735	1.7735	5.1873	4.2007	3.9291	5.1873	4.2007	3.9291
H11	3.2272	2.1706	2.8955	1.0965	3.5571	2.8596	3.4984	4.1591	3.8631	1.7735		1.7660	4.4554	4.0865	3.1784	3.9043	3.0048	2.3639
H12	3.2272	2.1706	2.8955	1.0965	2.8596	3.5571	3.4984	4.1591	3.8631	1.7735	1.7660		3.9043	3.0048	2.3639	4.4554	4.0865	3.1784
H13	4.4297	3.4806	2.1806	4.1812	1.0968	2.7955	5.4121	4.4886	2.4582	5.1873	4.4554	3.9043		1.7778	1.7695	2.6088	3.8069	3.1304
H14	3.4904	2.7443	2.1879	3.4066	1.0959	3.4942	4.3056	3.6919	2.5245	4.2007	4.0865	3.0048	1.7778		1.7777	3.8069	4.3437	3.7766
H15	4.0848	2.8636	2.1922	2.9162	1.0962	2.7712	4.8537	4.5651	3.0741	3.9291	3.1784	2.3639	1.7695	1.7777		3.1304	3.7766	2.5560
H16	4.4297	3.4806	2.1806	4.1812	2.7955	1.0968	5.4121	4.4886	2.4582	5.1873	3.9043	4.4554	2.6088	3.8069	3.1304		1.7778	1.7695
H17	3.4904	2.7443	2.1879	3.4066	3.4942	1.0959	4.3056	3.6919	2.5245	4.2007	3.0048	4.0865	3.8069	4.3437	3.7766	1.7778		1.7777
H18	4.0848	2.8636	2.1922	2.9162	2.7712	1.0962	4.8537	4.5651	3.0741	3.9291	2.3639	3.1784	3.1304	3.7766	2.5560	1.7695	1.7777

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	120.770	C1	C2	C4	121.188
C2	C1	H7	121.672	C2	C1	H8	121.286
C2	C3	C5	111.669	C2	C3	C6	111.669
C2	C3	H9	107.115	C2	C4	H10	110.650
C2	C4	H11	111.291	C2	C4	H12	111.291
C3	C2	C4	118.043	C3	C5	H13	110.273
C3	C5	H14	110.906	C3	C5	H15	111.230
C3	C6	H16	110.273	C3	C6	H17	110.906
C3	C6	H18	111.230	C5	C3	C6	110.468
C5	C3	H9	107.856	C6	C3	H9	107.856
H7	C1	H8	117.042	H10	C4	H11	108.090
H10	C4	H12	108.090	H11	C4	H12	107.278
H13	C5	H14	108.346	H13	C5	H15	107.595
H14	C5	H15	108.377	H16	C6	H17	108.346
H16	C6	H18	107.595	H17	C6	H18	108.377

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-121G*

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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Calc. vs exp. Bad Vib. HF vs MP2 Bad scale factors Low excited states Oddities NaCN Is not linear FAQ Help Units Choose Units Energy Bond length Rotational Constant Moment of Inertia Dipole and Quadrupole Polarizability Explanations Hartree cm-1 Debye Credits Just show me Show me a calculated geometry Summary Using older interface Limit Basis sets Method options List Recent molecules Choose a few Molecules Number of atoms By heavy atoms Diatomics InChI Deuterated Dimers Geometry Point group Point group count Bonds types Isodesmic reactions Bad point group Multiple conformers, states Vibrations Big anharmonicity Energy Enthalpy at 0 Kelvin Similar molecules Similar Isomers Cis/trans Tautomers Multiple conformers, states Ions, Dipoles, etc. List Ions Ionization changes point group Dipole Quadrupole Polarizability Proton Affinities Index of CCCBDB Feedback Error form Wants
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All results from a given calculation for C6H12 (2,3-dimethylbut-1-ene)

using model chemistry: MP2/CEP-121G*

States and conformations

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