CCCBDB calculation results Page

State	Conformation	minimum conformation	conformer description	state description
1	1	yes	C2H	¹A_g

Energy calculated at MP2/3-21G*

	hartrees
Energy at 0K	-234.627735
Energy at 298.15K	-234.643037
HF Energy	-234.068085
Nuclear repulsion energy	260.778998

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_g	3173	3019	0.00
2	A_g	3143	2990	0.00
3	A_g	3077	2927	0.00
4	A_g	3051	2903	0.00
5	A_g	1624	1545	0.00
6	A_g	1602	1524	0.00
7	A_g	1501	1428	0.00
8	A_g	1423	1354	0.00
9	A_g	1268	1206	0.00
10	A_g	1241	1181	0.00
11	A_g	960	914	0.00
12	A_g	764	727	0.00
13	A_g	509	484	0.00
14	A_g	402	382	0.00
15	A_g	246	234	0.00
16	A_u	3172	3018	48.89
17	A_u	3137	2984	0.01
18	A_u	3073	2924	26.85
19	A_u	1609	1531	5.20
20	A_u	1586	1508	1.52
21	A_u	1481	1409	11.57
22	A_u	1400	1332	2.77
23	A_u	1098	1044	2.77
24	A_u	1011	962	0.28
25	A_u	978	931	3.26
26	A_u	323	307	0.00
27	A_u	212	202	0.03
28	A_u	60	57	0.00
29	B_g	3157	3003	0.00
30	B_g	3137	2985	0.00
31	B_g	3072	2922	0.00
32	B_g	1594	1516	0.00
33	B_g	1590	1512	0.00
34	B_g	1472	1401	0.00
35	B_g	1414	1345	0.00
36	B_g	1201	1143	0.00
37	B_g	995	947	0.00
38	B_g	970	923	0.00
39	B_g	443	422	0.00
40	B_g	224	213	0.00
41	B_u	3161	3007	60.67
42	B_u	3145	2992	114.20
43	B_u	3075	2925	53.09
44	B_u	3066	2916	12.79
45	B_u	1609	1531	19.29
46	B_u	1602	1524	14.54
47	B_u	1491	1418	15.82
48	B_u	1374	1307	3.85
49	B_u	1227	1167	8.00
50	B_u	1061	1009	10.22
51	B_u	867	825	2.27
52	B_u	422	402	0.27
53	B_u	356	339	0.19
54	B_u	232	220	0.01

Unscaled Zero Point Vibrational Energy (zpe) 42540.0 cm^-1
Scaled (by 0.9513) Zero Point Vibrational Energy (zpe) 40468.3 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
0.13874	0.09486	0.06175

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

Geometric Data calculated at MP2/3-21G*

Point Group is C_2h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.779	0.000
C2	0.000	-0.779	0.000
H3	-1.051	1.107	0.000
H4	1.051	-1.107	0.000
C5	0.699	1.354	1.262
C6	0.699	1.354	-1.262
C7	-0.699	-1.354	1.262
C8	-0.699	-1.354	-1.262
H9	1.729	0.979	1.316
H10	1.729	0.979	-1.316
H11	-1.729	-0.979	1.316
H12	-1.729	-0.979	-1.316
H13	0.733	2.448	1.205
H14	0.174	1.076	2.180
H15	0.733	2.448	-1.205
H16	0.174	1.076	-2.180
H17	-0.733	-2.448	1.205
H18	-0.174	-1.076	2.180
H19	-0.733	-2.448	-1.205
H20	-0.174	-1.076	-2.180

Atom - Atom Distances (Å)

	C1	C2	H3	H4	C5	C6	C7	C8	H9	H10	H11	H12	H13	H14	H15	H16	H17	H18	H19	H20
C1		1.5577	1.1008	2.1589	1.5525	1.5525	2.5745	2.5745	2.1817	2.1817	2.7944	2.7944	2.1858	2.2074	2.1858	2.2074	3.5221	2.8680	3.5221	2.8680
C2	1.5577		2.1589	1.1008	2.5745	2.5745	1.5525	1.5525	2.7944	2.7944	2.1817	2.1817	3.5221	2.8680	3.5221	2.8680	2.1858	2.2074	2.1858	2.2074
H3	1.1008	2.1589		3.0527	2.1709	2.1709	2.7878	2.7878	3.0778	3.0778	2.5577	2.5577	2.5364	2.5011	2.5364	2.5011	3.7677	3.2076	3.7677	3.2076
H4	2.1589	1.1008	3.0527		2.7878	2.7878	2.1709	2.1709	2.5577	2.5577	3.0778	3.0778	3.7677	3.2076	3.7677	3.2076	2.5364	2.5011	2.5364	2.5011
C5	1.5525	2.5745	2.1709	2.7878		2.5231	3.0471	3.9561	1.0974	2.8010	3.3668	4.2399	1.0965	1.0937	2.6990	3.4926	4.0633	2.7407	4.7532	4.3028
C6	1.5525	2.5745	2.1709	2.7878	2.5231		3.9561	3.0471	2.8010	1.0974	4.2399	3.3668	2.6990	3.4926	1.0965	1.0937	4.7532	4.3028	4.0633	2.7407
C7	2.5745	1.5525	2.7878	2.1709	3.0471	3.9561		2.5231	3.3668	4.2399	1.0974	2.8010	4.0633	2.7407	4.7532	4.3028	1.0965	1.0937	2.6990	3.4926
C8	2.5745	1.5525	2.7878	2.1709	3.9561	3.0471	2.5231		4.2399	3.3668	2.8010	1.0974	4.7532	4.3028	4.0633	2.7407	2.6990	3.4926	1.0965	1.0937
H9	2.1817	2.7944	3.0778	2.5577	1.0974	2.8010	3.3668	4.2399		2.6321	3.9728	4.7656	1.7787	1.7811	3.0836	3.8275	4.2209	2.9309	4.9154	4.4797
H10	2.1817	2.7944	3.0778	2.5577	2.8010	1.0974	4.2399	3.3668	2.6321		4.7656	3.9728	3.0836	3.8275	1.7787	1.7811	4.9154	4.4797	4.2209	2.9309
H11	2.7944	2.1817	2.5577	3.0778	3.3668	4.2399	1.0974	2.8010	3.9728	4.7656		2.6321	4.2209	2.9309	4.9154	4.4797	1.7787	1.7811	3.0836	3.8275
H12	2.7944	2.1817	2.5577	3.0778	4.2399	3.3668	2.8010	1.0974	4.7656	3.9728	2.6321		4.9154	4.4797	4.2209	2.9309	3.0836	3.8275	1.7787	1.7811
H13	2.1858	3.5221	2.5364	3.7677	1.0965	2.6990	4.0633	4.7532	1.7787	3.0836	4.2209	4.9154		1.7736	2.4106	3.6956	5.1116	3.7679	5.6515	4.9708
H14	2.2074	2.8680	2.5011	3.2076	1.0937	3.4926	2.7407	4.3028	1.7811	3.8275	2.9309	4.4797	1.7736		3.6956	4.3606	3.7679	2.1805	4.9708	4.8754
H15	2.1858	3.5221	2.5364	3.7677	2.6990	1.0965	4.7532	4.0633	3.0836	1.7787	4.9154	4.2209	2.4106	3.6956		1.7736	5.6515	4.9708	5.1116	3.7679
H16	2.2074	2.8680	2.5011	3.2076	3.4926	1.0937	4.3028	2.7407	3.8275	1.7811	4.4797	2.9309	3.6956	4.3606	1.7736		4.9708	4.8754	3.7679	2.1805
H17	3.5221	2.1858	3.7677	2.5364	4.0633	4.7532	1.0965	2.6990	4.2209	4.9154	1.7787	3.0836	5.1116	3.7679	5.6515	4.9708		1.7736	2.4106	3.6956
H18	2.8680	2.2074	3.2076	2.5011	2.7407	4.3028	1.0937	3.4926	2.9309	4.4797	1.7811	3.8275	3.7679	2.1805	4.9708	4.8754	1.7736		3.6956	4.3606
H19	3.5221	2.1858	3.7677	2.5364	4.7532	4.0633	2.6990	1.0965	4.9154	4.2209	3.0836	1.7787	5.6515	4.9708	5.1116	3.7679	2.4106	3.6956		1.7736
H20	2.8680	2.2074	3.2076	2.5011	4.3028	2.7407	3.4926	1.0937	4.4797	2.9309	3.8275	1.7811	4.9708	4.8754	3.7679	2.1805	3.6956	4.3606	1.7736

picture of Butane, 2,3-dimethyl- state 1 conformation 1

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	H4	107.348	C1	C2	C7	111.741
C1	C2	C8	111.741	C1	C5	H9	109.637
C1	C5	H13	110.006	C1	C5	H14	111.885
C1	C6	H10	109.637	C1	C6	H15	110.006
C1	C6	H16	111.885	C2	C1	H3	107.348
C2	C1	C5	111.741	C2	C1	C6	111.741
C2	C7	H11	109.637	C2	C7	H17	110.006
C2	C7	H18	111.885	C2	C8	H12	109.637
C2	C8	H19	110.006	C2	C8	H20	111.885
H3	C1	C5	108.609	H3	C1	C6	108.609
H4	C2	C7	108.609	H4	C2	C8	108.609
C5	C1	C6	108.696	C7	C2	C8	108.696
H9	C5	H13	108.333	H9	C5	H14	108.749
H10	C6	H15	108.333	H10	C6	H16	108.749
H11	C7	H17	108.333	H11	C7	H18	108.749
H12	C8	H19	108.333	H12	C8	H20	108.749
H13	C5	H14	108.147	H15	C6	H16	108.147
H17	C7	H18	108.147	H19	C8	H20	108.147

Electronic energy levels

Electronic state

Charges, Dipole, Quadrupole and Polarizability

All results from a given calculation for C₆H₁₄ (Butane, 2,3-dimethyl-)

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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All results from a given calculation for C6H14 (Butane, 2,3-dimethyl-)

using model chemistry: MP2/3-21G*

States and conformations

All results from a given calculation for C₆H₁₄ (Butane, 2,3-dimethyl-)