CCCBDB calculation results Page

State	Conformation	minimum conformation	conformer description	state description
1	1	yes	C2H	¹A_g
1	2	no	C2	¹A
1	3	no	CI	¹A_g

Conformer 1 (C2H)

Jump to S1C2 S1C3

Energy calculated at PBEPBE/Def2TZVPP

	hartrees
Energy at 0K	-306.238998
Energy at 298.15K	-306.244827
HF Energy	-306.238998
Nuclear repulsion energy	225.106910

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 PBEPBE/Def2TZVPP

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3099	3062	0.00
2	A_g	2983	2947	0.00
3	A_g	1713	1693	0.00
4	A_g	1399	1382	0.00
5	A_g	1335	1319	0.00
6	A_g	1231	1217	0.00
7	A_g	972	961	0.00
8	A_g	666	658	0.00
9	A_g	500	494	0.00
10	A_g	350	346	0.00
11	A_u	3041	3005	2.37
12	A_u	1399	1382	21.56
13	A_u	907	896	5.17
14	A_u	332	328	3.46
15	A_u	105	104	0.01
16	A_u	45	44	11.32
17	B_g	3042	3005	0.00
18	B_g	1405	1388	0.00
19	B_g	1024	1011	0.00
20	B_g	598	591	0.00
21	B_g	102	101	0.00
22	B_u	3100	3062	11.37
23	B_u	2983	2947	0.19
24	B_u	1723	1702	233.86
25	B_u	1401	1384	30.07
26	B_u	1328	1311	85.44
27	B_u	1098	1085	81.91
28	B_u	883	872	26.86
29	B_u	526	520	36.22
30	B_u	231	228	16.08

Unscaled Zero Point Vibrational Energy (zpe) 19759.6 cm^-1
Scaled (by 0.9879) Zero Point Vibrational Energy (zpe) 19520.5 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 PBEPBE/Def2TZVPP

A	B	C
0.17482	0.11178	0.06993

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

Geometric Data calculated at PBEPBE/Def2TZVPP

Point Group is C_2h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.050	0.745	0.000
C2	0.050	-0.745	0.000
C3	1.188	1.577	0.000
C4	-1.188	-1.577	0.000
O5	-1.188	1.248	0.000
O6	1.188	-1.248	0.000
H7	0.913	2.635	0.000
H8	-0.913	-2.635	0.000
H9	1.801	1.347	0.882
H10	1.801	1.347	-0.882
H11	-1.801	-1.347	0.882
H12	-1.801	-1.347	-0.882

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.4940	1.4910	2.5859	1.2437	2.3463	2.1207	3.4886	2.1364	2.1364	2.8670	2.8670
C2	1.4940		2.5859	1.4910	2.3463	1.2437	3.4886	2.1207	2.8670	2.8670	2.1364	2.1364
C3	1.4910	2.5859		3.9482	2.3978	2.8251	1.0931	4.7065	1.0982	1.0982	4.2727	4.2727
C4	2.5859	1.4910	3.9482		2.8251	2.3978	4.7065	1.0931	4.2727	4.2727	1.0982	1.0982
O5	1.2437	2.3463	2.3978	2.8251		3.4456	2.5168	3.8928	3.1171	3.1171	2.8086	2.8086
O6	2.3463	1.2437	2.8251	2.3978	3.4456		3.8928	2.5168	2.8086	2.8086	3.1171	3.1171
H7	2.1207	3.4886	1.0931	4.7065	2.5168	3.8928		5.5770	1.7957	1.7957	4.8985	4.8985
H8	3.4886	2.1207	4.7065	1.0931	3.8928	2.5168	5.5770		4.8985	4.8985	1.7957	1.7957
H9	2.1364	2.8670	1.0982	4.2727	3.1171	2.8086	1.7957	4.8985		1.7634	4.4973	4.8307
H10	2.1364	2.8670	1.0982	4.2727	3.1171	2.8086	1.7957	4.8985	1.7634		4.8307	4.4973
H11	2.8670	2.1364	4.2727	1.0982	2.8086	3.1171	4.8985	1.7957	4.4973	4.8307		1.7634
H12	2.8670	2.1364	4.2727	1.0982	2.8086	3.1171	4.8985	1.7957	4.8307	4.4973	1.7634

picture of 2,3-Butanedione state 1 conformation 1

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	120.060	C1	C2	O6	117.687
C1	C3	H7	109.337	C1	C3	H9	110.275
C1	C3	H10	110.275	C2	C1	C3	120.060
C2	C1	O5	117.687	C2	C4	H8	109.337
C2	C4	H11	110.275	C2	C4	H12	110.275
C3	C1	O5	122.253	C4	C2	O6	122.253
H7	C3	H9	110.060	H7	C3	H10	110.060
H8	C4	H11	110.060	H8	C4	H12	110.060
H9	C3	H10	106.809	H11	C4	H12	106.809

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at PBEPBE/Def2TZVPP Charges (e)

Number	Element	Mulliken
1	C	0.132
2	C	0.132
3	C	-0.211
4	C	-0.211
5	O	-0.234
6	O	-0.234
7	H	0.105
8	H	0.105
9	H	0.104
10	H	0.104
11	H	0.104
12	H	0.104

Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)

	x	y	z	Total
	0.000	0.000	0.000	0.000
CHELPG
AIM
ESP

Electric Quadrupole moment
Quadrupole components in D Å

Primitive
	x	y	z
x	-38.574	7.462	0.000
y	7.462	-36.935	0.000
z	0.000	0.000	-33.937

Traceless
	x	y	z
x	-3.138	7.462	0.000
y	7.462	-0.680	0.000
z	0.000	0.000	3.818

Polar
3z²-r²	7.636
x²-y²	-1.639
xy	7.462
xz	0.000
yz	0.000

Polarizabilities
Components of the polarizability tensor.
Units are Å³ (Angstrom cubed)
Change units.

	x	y	z
x	9.587	0.362	0.000
y	0.362	8.993	0.000
z	0.000	0.000	5.873

<r²> (average value of r²) Å²

<r²>	164.109
(<r²>)^1/2	12.811

Conformer 2 (C2)

Jump to S1C1 S1C3

Energy calculated at PBEPBE/Def2TZVPP

	hartrees
Energy at 0K	-306.238998
Energy at 298.15K	-306.244831
HF Energy	-306.238998
Nuclear repulsion energy	225.123696

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 PBEPBE/Def2TZVPP

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A	3099	3061	0.00
2	A	3041	3004	2.36
3	A	2982	2946	0.00
4	A	1714	1693	0.00
5	A	1399	1382	0.00
6	A	1399	1382	21.57
7	A	1336	1319	0.00
8	A	1232	1217	0.00
9	A	973	961	0.00
10	A	908	897	5.18
11	A	667	659	0.00
12	A	500	494	0.00
13	A	350	346	0.00
14	A	331	327	3.45
15	A	107	105	0.00
16	A	45	44	11.34
17	B	3099	3062	11.38
18	B	3041	3004	0.00
19	B	2982	2946	0.19
20	B	1723	1702	233.99
21	B	1405	1388	0.00
22	B	1401	1384	30.08
23	B	1328	1312	85.69
24	B	1098	1085	81.92
25	B	1024	1011	0.00
26	B	883	873	26.58
27	B	599	591	0.00
28	B	526	520	36.29
29	B	231	228	16.09
30	B	103	102	0.00

Unscaled Zero Point Vibrational Energy (zpe) 19761.2 cm^-1
Scaled (by 0.9879) Zero Point Vibrational Energy (zpe) 19522.1 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 PBEPBE/Def2TZVPP

A	B	C
0.17486	0.11179	0.06994

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

Geometric Data calculated at PBEPBE/Def2TZVPP

Point Group is C₂

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.075	0.777	-0.027
C2	0.075	-0.777	-0.027
C3	1.193	1.579	0.068
C4	-1.193	-1.579	0.068
O5	-1.193	1.269	-0.077
O6	1.193	-1.269	-0.077
H7	1.083	2.532	-0.463
H8	-1.083	-2.532	-0.463
H9	1.378	1.811	1.130
H10	2.045	0.997	-0.299
H11	-1.378	-1.811	1.130
H12	-2.045	-0.997	-0.299

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5620	1.5039	2.6101	1.2223	2.4085	2.1469	3.4865	2.1258	2.1488	3.1198	2.6650
C2	1.5620		2.6101	1.5039	2.4085	1.2223	3.4865	2.1469	3.1198	2.6650	2.1258	2.1488
C3	1.5039	2.6101		3.9589	2.4108	2.8524	1.0963	4.7290	1.1023	1.0947	4.3852	4.1544
C4	2.6101	1.5039	3.9589		2.8524	2.4108	4.7290	1.0963	4.3852	4.1544	1.1023	1.0947
O5	1.2223	2.4085	2.4108	2.8524		3.4842	2.6311	3.8224	2.8913	3.2569	3.3129	2.4316
O6	2.4085	1.2223	2.8524	2.4108	3.4842		3.8224	2.6311	3.3129	2.4316	2.8913	3.2569
H7	2.1469	3.4865	1.0963	4.7290	2.6311	3.8224		5.5072	1.7737	1.8186	5.2392	4.7184
H8	3.4865	2.1469	4.7290	1.0963	3.8224	2.6311	5.5072		5.2392	4.7184	1.7737	1.8186
H9	2.1258	3.1198	1.1023	4.3852	2.8913	3.3129	1.7737	5.2392		1.7739	4.5506	4.6520
H10	2.1488	2.6650	1.0947	4.1544	3.2569	2.4316	1.8186	4.7184	1.7739		4.6520	4.5501
H11	3.1198	2.1258	4.3852	1.1023	3.3129	2.8913	5.2392	1.7737	4.5506	4.6520		1.7739
H12	2.6650	2.1488	4.1544	1.0947	2.4316	3.2569	4.7184	1.8186	4.6520	4.5501	1.7739

picture of 2,3-Butanedione state 1 conformation 2

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	116.704	C1	C2	O6	119.270
C1	C3	H7	110.334	C1	C3	H9	108.321
C1	C3	H10	110.575	C2	C1	C3	116.704
C2	C1	O5	119.270	C2	C4	H8	110.334
C2	C4	H11	108.321	C2	C4	H12	110.575
C3	C1	O5	124.010	C4	C2	O6	124.010
H7	C3	H9	107.560	H7	C3	H10	112.202
H8	C4	H11	107.560	H8	C4	H12	112.202
H9	C3	H10	107.690	H11	C4	H12	107.690

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at PBEPBE/Def2TZVPP Charges (e)

Number	Element	Mulliken
1	C	0.132
2	C	0.132
3	C	-0.211
4	C	-0.211
5	O	-0.234
6	O	-0.234
7	H	0.105
8	H	0.105
9	H	0.104
10	H	0.104
11	H	0.104
12	H	0.104

Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)

	x	y	z	Total
	0.000	0.000	0.001	0.001
CHELPG
AIM
ESP

Electric Quadrupole moment
Quadrupole components in D Å

Primitive
	x	y	z
x	-38.570	7.466	0.000
y	7.466	-36.934	0.000
z	0.000	0.000	-33.936

Traceless
	x	y	z
x	-3.135	7.466	0.000
y	7.466	-0.681	0.000
z	0.000	0.000	3.815

Polar
3z²-r²	7.630
x²-y²	-1.636
xy	7.466
xz	0.000
yz	0.000

Polarizabilities
Components of the polarizability tensor.
Units are Å³ (Angstrom cubed)
Change units.

	x	y	z
x	9.586	0.362	0.000
y	0.362	8.992	0.000
z	0.000	0.000	5.873

<r²> (average value of r²) Å²

<r²>	164.088
(<r²>)^1/2	12.810

Conformer 3 (CI)

Jump to S1C1 S1C2

Energy calculated at PBEPBE/Def2TZVPP

	hartrees
Energy at 0K	-306.238986
Energy at 298.15K	-306.244785
HF Energy	-306.238986
Nuclear repulsion energy	225.118194

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 PBEPBE/Def2TZVPP

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3099	3061	0.00
2	A_g	3041	3005	0.00
3	A_g	2982	2946	0.00
4	A_g	1714	1693	0.00
5	A_g	1403	1386	0.00
6	A_g	1399	1382	0.00
7	A_g	1332	1316	0.00
8	A_g	1232	1217	0.00
9	A_g	1023	1011	0.00
10	A_g	972	960	0.00
11	A_g	666	658	0.00
12	A_g	595	588	0.00
13	A_g	499	493	0.00
14	A_g	349	345	0.00
15	A_g	99	98	0.00
16	A_u	3099	3062	11.37
17	A_u	3041	3004	2.36
18	A_u	2982	2946	0.20
19	A_u	1723	1702	233.90
20	A_u	1401	1384	30.34
21	A_u	1397	1380	21.57
22	A_u	1324	1308	85.13
23	A_u	1098	1085	83.23
24	A_u	906	895	5.13
25	A_u	882	872	25.97
26	A_u	526	519	36.13
27	A_u	328	324	3.49
28	A_u	230	227	16.02
29	A_u	102	101	0.01
30	A_u	41	40	11.29

Unscaled Zero Point Vibrational Energy (zpe) 19742.3 cm^-1
Scaled (by 0.9879) Zero Point Vibrational Energy (zpe) 19503.4 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 PBEPBE/Def2TZVPP

A	B	C
0.17486	0.11177	0.06994

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

Geometric Data calculated at PBEPBE/Def2TZVPP

Point Group is C_i

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	0.008	0.000	-0.779
C2	-0.008	-0.000	0.779
C3	1.359	-0.000	-1.432
C4	-1.359	0.000	1.432
O5	-1.048	-0.000	-1.390
O6	1.048	0.000	1.390
H7	1.940	0.873	-1.097
H8	-1.940	-0.873	1.097
H9	1.940	-0.872	-1.097
H10	1.258	-0.000	-2.521
H11	-1.940	0.872	1.097
H12	-1.258	0.000	2.521

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5590	1.5006	2.5996	1.2198	2.4064	2.1439	2.8422	2.1439	2.1443	2.8419	3.5353
C2	1.5590		2.5996	1.5006	2.4064	1.2198	2.8422	2.1439	2.8419	3.5353	2.1439	2.1443
C3	1.5006	2.5996		3.9483	2.4076	2.8392	1.1003	4.2477	1.1003	1.0944	4.2475	4.7410
C4	2.5996	1.5006	3.9483		2.8392	2.4076	4.2477	1.1003	4.2475	4.7410	1.1003	1.0944
O5	1.2198	2.4064	2.4076	2.8392		3.4823	3.1267	2.7832	3.1267	2.5686	2.7829	3.9174
O6	2.4064	1.2198	2.8392	2.4076	3.4823		2.7832	3.1267	2.7829	3.9174	3.1267	2.5686
H7	2.1439	2.8422	1.1003	4.2477	3.1267	2.7832		4.7873	1.7450	1.8040	4.4578	4.9077
H8	2.8422	2.1439	4.2477	1.1003	2.7832	3.1267	4.7873		4.4578	4.9077	1.7450	1.8040
H9	2.1439	2.8419	1.1003	4.2475	3.1267	2.7829	1.7450	4.4578		1.8040	4.7870	4.9075
H10	2.1443	3.5353	1.0944	4.7410	2.5686	3.9174	1.8040	4.9077	1.8040		4.9075	5.6357
H11	2.8419	2.1439	4.2475	1.1003	2.7829	3.1267	4.4578	1.7450	4.7870	4.9075		1.8040
H12	3.5353	2.1443	4.7410	1.0944	3.9174	2.5686	4.9077	1.8040	4.9075	5.6357	1.8040

picture of 2,3-Butanedione state 1 conformation 3

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	116.330	C1	C2	O6	119.489
C1	C3	H7	110.084	C1	C3	H9	110.080
C1	C3	H10	110.466	C2	C1	C3	116.330
C2	C1	O5	119.489	C2	C4	H8	110.084
C2	C4	H11	110.080	C2	C4	H12	110.466
C3	C1	O5	124.181	C4	C2	O6	124.181
H7	C3	H9	104.931	H7	C3	H10	110.575
H8	C4	H11	104.931	H8	C4	H12	110.575
H9	C3	H10	110.575	H11	C4	H12	110.575

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at PBEPBE/Def2TZVPP Charges (e)

Number	Element	Mulliken
1	C	0.132
2	C	0.132
3	C	-0.211
4	C	-0.211
5	O	-0.234
6	O	-0.234
7	H	0.104
8	H	0.104
9	H	0.104
10	H	0.105
11	H	0.104
12	H	0.105

Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)

	x	y	z	Total
	0.000	0.000	0.000	0.000
CHELPG
AIM
ESP

Electric Quadrupole moment
Quadrupole components in D Å

Primitive
	x	y	z
x	-36.901	0.003	-7.460
y	0.003	-33.934	0.001
z	-7.460	0.001	-38.607

Traceless
	x	y	z
x	-0.631	0.003	-7.460
y	0.003	3.820	0.001
z	-7.460	0.001	-3.189

Polar
3z²-r²	-6.378
x²-y²	-2.967
xy	0.003
xz	-7.460
yz	0.001

Polarizabilities
Components of the polarizability tensor.
Units are Å³ (Angstrom cubed)
Change units.

	x	y	z
x	9.658	-0.001	-0.288
y	-0.001	5.872	-0.000
z	-0.288	-0.000	8.920

<r²> (average value of r²) Å²

<r²>	164.096
(<r²>)^1/2	12.810

All results from a given calculation for C₄H₆O₂ (2,3-Butanedione)

using model chemistry: PBEPBE/Def2TZVPP

States and conformations

Conformer 1 (C2H)

Conformer 2 (C2)

Conformer 3 (CI)

	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 C4H6O2 (2,3-Butanedione)

using model chemistry: PBEPBE/Def2TZVPP

States and conformations

Conformer 1 (C2H)

Conformer 2 (C2)

Conformer 3 (CI)

All results from a given calculation for C₄H₆O₂ (2,3-Butanedione)