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	-233.446516
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	3085	19.00
2	A'	3162	3008	47.14
3	A'	3160	3006	3.39
4	A'	3152	2998	9.02
5	A'	3150	2996	53.09
6	A'	3081	2931	14.16
7	A'	3076	2926	9.78
8	A'	3067	2917	14.25
9	A'	1697	1614	3.89
10	A'	1609	1531	6.46
11	A'	1607	1529	9.18
12	A'	1596	1519	7.67
13	A'	1528	1453	0.22
14	A'	1496	1423	5.55
15	A'	1483	1411	8.15
16	A'	1394	1327	2.68
17	A'	1324	1260	0.56
18	A'	1241	1181	2.89
19	A'	1160	1103	13.48
20	A'	1063	1011	1.58
21	A'	974	926	0.34
22	A'	894	851	1.34
23	A'	719	684	0.96
24	A'	527	501	1.70
25	A'	454	432	0.36
26	A'	337	321	0.30
27	A'	288	274	0.20
28	A'	265	252	0.16
29	A"	3158	3004	4.15
30	A"	3149	2995	18.90
31	A"	3142	2989	13.23
32	A"	3076	2926	17.66
33	A"	1602	1524	0.33
34	A"	1590	1513	0.74
35	A"	1582	1505	8.55
36	A"	1473	1402	5.41
37	A"	1401	1333	1.57
38	A"	1157	1101	1.94
39	A"	1120	1065	2.23
40	A"	1001	952	0.66
41	A"	974	927	1.13
42	A"	935	889	45.28
43	A"	758	721	0.68
44	A"	559	532	8.04
45	A"	279	265	0.07
46	A"	221	210	0.56
47	A"	162	154	0.26
48	A"	27	26	0.06

Unscaled Zero Point Vibrational Energy (zpe) 37055.6 cm^-1
Scaled (by 0.9513) Zero Point Vibrational Energy (zpe) 35251.0 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 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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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: MP2/3-21G*

States and conformations

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