CCCBDB calculation results Page

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

Energy calculated at QCISD/3-21G*

	hartrees
Energy at 0K	-233.505183
Energy at 298.15K	-233.517468
HF Energy	-232.881099
Nuclear repulsion energy	241.314862

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 QCISD/3-21G*

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A'	3183	3059	20.64
2	A'	3109	2988	11.99
3	A'	3097	2977	42.49
4	A'	3089	2969	4.29
5	A'	3087	2966	67.41
6	A'	3027	2909	13.70
7	A'	3021	2904	10.28
8	A'	3016	2899	14.42
9	A'	1698	1632	5.31
10	A'	1585	1524	5.26
11	A'	1584	1523	9.56
12	A'	1574	1513	7.43
13	A'	1510	1452	0.39
14	A'	1480	1422	5.62
15	A'	1469	1411	7.68
16	A'	1382	1328	2.62
17	A'	1313	1262	0.52
18	A'	1226	1178	2.82
19	A'	1148	1103	11.94
20	A'	1052	1012	1.34
21	A'	962	924	0.24
22	A'	881	847	1.08
23	A'	709	681	0.85
24	A'	521	501	1.51
25	A'	450	433	0.37
26	A'	334	321	0.25
27	A'	286	275	0.18
28	A'	258	248	0.13
29	A"	3093	2972	3.98
30	A"	3084	2964	22.41
31	A"	3077	2957	15.10
32	A"	3020	2902	19.21
33	A"	1580	1518	0.47
34	A"	1567	1506	0.73
35	A"	1561	1500	7.78
36	A"	1458	1401	5.30
37	A"	1385	1331	1.34
38	A"	1142	1098	1.77
39	A"	1103	1061	2.25
40	A"	988	949	0.72
41	A"	962	924	1.02
42	A"	931	895	41.06
43	A"	741	712	0.59
44	A"	552	530	7.53
45	A"	275	264	0.10
46	A"	217	208	0.51
47	A"	156	150	0.20
48	A"	21	20	0.06

Unscaled Zero Point Vibrational Energy (zpe) 36481.3 cm^-1
Scaled (by 0.9611) Zero Point Vibrational Energy (zpe) 35062.1 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 QCISD/3-21G*

A	B	C
0.14430	0.08170	0.08084

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

Geometric Data calculated at QCISD/3-21G*

Point Group is C_s

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-1.773	-1.078	0.000
C2	-0.490	-0.671	0.000
C3	-0.128	0.823	0.000
C4	0.667	-1.677	0.000
C5	0.667	1.218	1.280
C6	0.667	1.218	-1.280
H7	-2.044	-2.135	0.000
H8	-2.602	-0.368	0.000
H9	-1.076	1.387	0.000
H10	0.276	-2.704	0.000
H11	1.301	-1.548	-0.890
H12	1.301	-1.548	0.890
H13	0.836	2.305	1.299
H14	0.109	0.932	2.183
H15	1.646	0.717	1.295
H16	0.836	2.305	-1.299
H17	0.109	0.932	-2.183
H18	1.646	0.717	-1.295

Atom - Atom Distances (Å)

	C1	C2	C3	C4	C5	C6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17	H18
C1		1.3462	2.5142	2.5129	3.5871	3.5871	1.0911	1.0912	2.5620	2.6162	3.2347	3.2347	4.4657	3.5136	4.0730	4.4657	3.5136	4.0730
C2	1.3462		1.5373	1.5333	2.5586	2.5586	2.1350	2.1333	2.1399	2.1729	2.1839	2.1839	3.5076	2.7733	2.8575	3.5076	2.7733	2.8575
C3	2.5142	1.5373		2.6234	1.5580	1.5580	3.5244	2.7454	1.1030	3.5505	2.9083	2.9083	2.1939	2.1984	2.1991	2.1939	2.1984	2.1991
C4	2.5129	1.5333	2.6234		3.1651	3.1651	2.7496	3.5213	3.5252	1.0994	1.1002	1.1002	4.1918	3.4467	2.8921	4.1918	3.4467	2.8921
C5	3.5871	2.5586	1.5580	3.1651		2.5602	4.4981	3.8524	2.1695	4.1443	3.5726	2.8645	1.1004	1.0996	1.0995	2.8038	3.5195	2.8001
C6	3.5871	2.5586	1.5580	3.1651	2.5602		4.4981	3.8524	2.1695	4.1443	2.8645	3.5726	2.8038	3.5195	2.8001	1.1004	1.0996	1.0995
H7	1.0911	2.1350	3.5244	2.7496	4.4981	4.4981		1.8532	3.6529	2.3889	3.5105	3.5105	5.4496	4.3362	4.8400	5.4496	4.3362	4.8400
H8	1.0912	2.1333	2.7454	3.5213	3.8524	3.8524	1.8532		2.3256	3.7069	4.1731	4.1731	4.5444	3.7149	4.5713	4.5444	3.7149	4.5713
H9	2.5620	2.1399	1.1030	3.5252	2.1695	2.1695	3.6529	2.3256		4.3091	3.8805	3.8805	2.4872	2.5252	3.0880	2.4872	2.5252	3.0880
H10	2.6162	2.1729	3.5505	1.0994	4.1443	4.1443	2.3889	3.7069	4.3091		1.7828	1.7828	5.2053	4.2440	3.9060	5.2053	4.2440	3.9060
H11	3.2347	2.1839	2.9083	1.1002	3.5726	2.8645	3.5105	4.1731	3.8805	1.7828		1.7806	4.4561	4.1248	3.1663	3.9028	3.0398	2.3267
H12	3.2347	2.1839	2.9083	1.1002	2.8645	3.5726	3.5105	4.1731	3.8805	1.7828	1.7806		3.9028	3.0398	2.3267	4.4561	4.1248	3.1663
H13	4.4657	3.5076	2.1939	4.1918	1.1004	2.8038	5.4496	4.5444	2.4872	5.2053	4.4561	3.9028		1.7883	1.7829	2.5975	3.8129	3.1475
H14	3.5136	2.7733	2.1984	3.4467	1.0996	3.5195	4.3362	3.7149	2.5252	4.2440	4.1248	3.0398	1.7883		1.7880	3.8129	4.3658	3.8086
H15	4.0730	2.8575	2.1991	2.8921	1.0995	2.8001	4.8400	4.5713	3.0880	3.9060	3.1663	2.3267	1.7829	1.7880		3.1475	3.8086	2.5902
H16	4.4657	3.5076	2.1939	4.1918	2.8038	1.1004	5.4496	4.5444	2.4872	5.2053	3.9028	4.4561	2.5975	3.8129	3.1475		1.7883	1.7829
H17	3.5136	2.7733	2.1984	3.4467	3.5195	1.0996	4.3362	3.7149	2.5252	4.2440	3.0398	4.1248	3.8129	4.3658	3.8086	1.7883		1.7880
H18	4.0730	2.8575	2.1991	2.8921	2.8001	1.0995	4.8400	4.5713	3.0880	3.9060	2.3267	3.1663	3.1475	3.8086	2.5902	1.7829	1.7880

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	121.218	C1	C2	C4	121.403
C2	C1	H7	121.966	C2	C1	H8	121.795
C2	C3	C5	111.498	C2	C3	C6	111.498
C2	C3	H9	107.141	C2	C4	H10	110.157
C2	C4	H11	110.976	C2	C4	H12	110.976
C3	C2	C4	117.379	C3	C5	H13	110.035
C3	C5	H14	110.434	C3	C5	H15	110.498
C3	C6	H16	110.035	C3	C6	H17	110.434
C3	C6	H18	110.498	C5	C3	C6	110.493
C5	C3	H9	108.014	C6	C3	H9	108.014
H7	C1	H8	116.240	H10	C4	H11	108.298
H10	C4	H12	108.298	H11	C4	H12	108.041
H13	C5	H14	108.750	H13	C5	H15	108.279
H14	C5	H15	108.789	H16	C6	H17	108.750
H16	C6	H18	108.279	H17	C6	H18	108.789

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability

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

using model chemistry: QCISD/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
	Home All data for one species Geometry Experimental Experimental Geometries Same bond/angle many molecules Internal Coordinates by type Bond angles Calculated Calculated geometry Rotational constant Moments of inertia Products of moments of inertia BSE Bond lengths Show me a calculated geometry Comparisons Bonds, angles Rotational Constants Products of moments of inertia Point group Bad Calculations Bad moment of inertia Tutorials and Explanations Angle formulas Vibrations Experimental Vibrational frequencies Calculated Frequencies Scale factors Reactions Entropies Ions List Ions Energy Calculated Ionization Energy Compare Ionzation energy Electron Affinity Calculated Electron affinity Compare Electron affinity Proton Affinity Calculated Proton affinity Compare Proton affinity Ionization changes point group Experimental One molecule all properties One property a few molecules Enthalpy of formation Entropy Integrated Heat Capacity Heat Capacity Rotational Constants Vibrational Frequencies Dipole moment Ionization Energy Polarizability Quadrupole Point Groups Geometry Experimental Geometries Internal Coordinates by type Bond angles Rotational Constants Point Groups Diatomic bond lengths Vibrations Vibrational frequencies Diatomic Triatomics Energy Atomization Energy Internal Rotation Electrostatics Dipole Quadrupole Polarizability Reference Data Reference states Spin Splittings Molecules with good enthalpy Enthalpy at 0 Kelvin Calculated Energy Optimized Energy Energy 298K Minimum conformation Hydrogen bonds H bond with counterpoise Reaction Reaction Energy 0K Reaction Energy 298K Internal Rotation Barriers to internal rotation Rotational barrier and dipole Rotational Barrier 2 molecules Orbital HOMO LUMO gap HOMO Orbital Energies Nuclear repulsion energy Correlation Full vs Frozen core energies Partial correlation energies Ion Calculated Ionization Energy Vertical ionization Energy Calculated Electron affinity Calculated Proton affinity Atom charge differences Excited State Singlet triplet gap Electronic state Transition state Basis Set Extrapolation BSE energy BSE Bond lengths Geometry Calculated geometry AIM bond orders One type of bond Rotation Rotational constant Products of moments of inertia Moments of inertia Inertial defects Second moments Point group State symmetry <r2> Sorted by r2 Z-matrix Bad Calculations Bad moment of inertia Bad Calculated Bond Lengths Bad point group Worst molecules Vibrations Frequencies Animated vibrations Anharmonic Zero point energy (ZPE) Scale Factors Scale factors Scale factor uncertainty Calculate a scale factor Why scale vibrations Set scaling factors Bad Calculations Bad Vib. HF vs MP2 Bad vib. Calc. vs exp. Big anharmonicity Electrostatics Charges Mulliken CHELP Aim ESP Dipole Dipole Dipole angle Dipole calculation types Quadrupole Polarizability Spin Spin density Entropy and Heat Capacity Entropy Reaction entropy Heat Capacity Reaction Reaction Energy 0K Reaction Energy 298K Isodesmic reactions Transition State Transition state Transition state frequencies Transition state geometries IRC Lookup by property By frequency Comparisons Geometry Bonds, angles Bond, angle, or dihedral DFT grid size on point group DFT grid on bond length Core correlation - bond length Same bond/angle many molecules Isoelectronic diatomics Isoelectronic triatomic angles Average bond lengths Rotation Rotational Constants Products of moments of inertia Point group Vibrations Vibrations 2 calculations Frequency differences One frequency Zero point energy Intensity Intensity for one mode Vibrational intensities Reduced mass comparison Anharmonic Triatomic Scale factors Energy Reaction Reaction Energy 0K Reaction Energy 298K Atomization 0K Atomization 298K Single point vs optimized DFT grid size on energy Semiempirical enthalpy Internal rotation Similar molecules Conformation Sets of isomers Sets of tautomers Isomers Entropy Entropy Heat capacity Entropy of several molecules Integrated heat capacity Reaction entropy Electrostatics Dipole Polarizability Several molecules Quadrupole Ion Compare Ionzation energy Koopman ionization energy Koopman IE for a few molecules Compare Electron affinity Compare Proton affinity Protonation Site Resources Info on Results Calculations Done Method and basis set List molecules One molecule Multiple conformers, states Multiple conformers, states Basis functions used I/O files Input/output files MOL file Z-matrix wfn files Glossary Conversion Forms B to I, I to B Angle formulas Integrated heat Capacity Calculating Enthalpy Links NIST Links NIST webbook bibliographic data CCCBDB Experimental data External links Basis Set Exchange Computational Chemistry List Thermochemistry in Gaussian Minnesota Database Collection Benchmark Energy and Geometry Point Groups Thermochemistry Thermochemistry Molecules with good enthalpy A → B + C Reference states Tutorials Vibrations Why scale vibrations Zero-point energies Entropy Methyl rotor entropy Entropy and conformations Energy Getting enthalpy of formation Vertical vs adiabatic IE Thermo from calculations Electrostatics Dipole parts by point group Quadrupoles Geometry Angle formulas Cost Cost Comparison Timings Comparison Bad Calculations Geometry Bad moment of inertia Bad Calculated Bond Lengths Bad point group Worst molecules Vibrations Bad vib. 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
You are here: Calculated > Energy > Optimized > Energy

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

using model chemistry: QCISD/3-21G*

States and conformations

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