CCCBDB calculation results Page

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

Conformer 1 (C2H)

Jump to S1C2 S1C3

Energy calculated at HF/Def2TZVPP

	hartrees
Energy at 0K	-304.813911
Energy at 298.15K	-304.820355
HF Energy	-304.813911
Nuclear repulsion energy	228.226685

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 HF/Def2TZVPP

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3285	2978	0.00
2	A_g	3187	2888	0.00
3	A_g	2007	1819	0.00
4	A_g	1577	1430	0.00
5	A_g	1534	1391	0.00
6	A_g	1406	1275	0.00
7	A_g	1107	1004	0.00
8	A_g	742	673	0.00
9	A_g	571	518	0.00
10	A_g	386	350	0.00
11	A_u	3247	2943	16.10
12	A_u	1584	1436	17.80
13	A_u	1062	962	4.22
14	A_u	395	358	12.54
15	A_u	142	129	0.12
16	A_u	50	45	13.02
17	B_g	3247	2943	0.00
18	B_g	1588	1439	0.00
19	B_g	1184	1073	0.00
20	B_g	682	618	0.00
21	B_g	144	130	0.00
22	B_u	3286	2978	23.08
23	B_u	3186	2888	4.42
24	B_u	1983	1798	379.87
25	B_u	1577	1430	27.22
26	B_u	1523	1381	37.61
27	B_u	1228	1113	82.68
28	B_u	981	889	21.04
29	B_u	589	534	58.73
30	B_u	255	231	18.56

Unscaled Zero Point Vibrational Energy (zpe) 21866.9 cm^-1
Scaled (by 0.9064) Zero Point Vibrational Energy (zpe) 19820.1 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 HF/Def2TZVPP

A	B	C
0.18258	0.11273	0.07150

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

Geometric Data calculated at HF/Def2TZVPP

Point Group is C_2h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.055	0.744	0.000
C2	0.055	-0.744	0.000
C3	1.162	1.595	0.000
C4	-1.162	-1.595	0.000
O5	-1.162	1.211	0.000
O6	1.162	-1.211	0.000
H7	0.867	2.632	0.000
H8	-0.867	-2.632	0.000
H9	1.762	1.380	0.875
H10	1.762	1.380	-0.875
H11	-1.762	-1.380	0.875
H12	-1.762	-1.380	-0.875

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.4911	1.4848	2.5874	1.2018	2.3025	2.1018	3.4723	2.1147	2.1147	2.8622	2.8622
C2	1.4911		2.5874	1.4848	2.3025	1.2018	3.4723	2.1018	2.8622	2.8622	2.1147	2.1147
C3	1.4848	2.5874		3.9466	2.3547	2.8066	1.0782	4.6891	1.0827	1.0827	4.2624	4.2624
C4	2.5874	1.4848	3.9466		2.8066	2.3547	4.6891	1.0782	4.2624	4.2624	1.0827	1.0827
O5	1.2018	2.3025	2.3547	2.8066		3.3568	2.4768	3.8551	3.0565	3.0565	2.8007	2.8007
O6	2.3025	1.2018	2.8066	2.3547	3.3568		3.8551	2.4768	2.8007	2.8007	3.0565	3.0565
H7	2.1018	3.4723	1.0782	4.6891	2.4768	3.8551		5.5430	1.7703	1.7703	4.8766	4.8766
H8	3.4723	2.1018	4.6891	1.0782	3.8551	2.4768	5.5430		4.8766	4.8766	1.7703	1.7703
H9	2.1147	2.8622	1.0827	4.2624	3.0565	2.8007	1.7703	4.8766		1.7500	4.4769	4.8067
H10	2.1147	2.8622	1.0827	4.2624	3.0565	2.8007	1.7703	4.8766	1.7500		4.8067	4.4769
H11	2.8622	2.1147	4.2624	1.0827	2.8007	3.0565	4.8766	1.7703	4.4769	4.8067		1.7500
H12	2.8622	2.1147	4.2624	1.0827	2.8007	3.0565	4.8766	1.7703	4.8067	4.4769	1.7500

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	120.791	C1	C2	O6	117.122
C1	C3	H7	109.144	C1	C3	H9	109.911
C1	C3	H10	109.911	C2	C1	C3	120.791
C2	C1	O5	117.122	C2	C4	H8	109.144
C2	C4	H11	109.911	C2	C4	H12	109.911
C3	C1	O5	122.087	C4	C2	O6	122.087
H7	C3	H9	110.014	H7	C3	H10	110.014
H8	C4	H11	110.014	H8	C4	H12	110.014
H9	C3	H10	107.835	H11	C4	H12	107.835

Electronic energy levels

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

Number	Element	Mulliken
1	C	0.287
2	C	0.287
3	C	-0.161
4	C	-0.161
5	O	-0.391
6	O	-0.391
7	H	0.108
8	H	0.108
9	H	0.079
10	H	0.079
11	H	0.079
12	H	0.079

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	-39.376	8.038	0.000
y	8.038	-36.876	0.000
z	0.000	0.000	-33.632

Traceless
	x	y	z
x	-4.123	8.038	0.000
y	8.038	-0.372	0.000
z	0.000	0.000	4.495

Polar
3z²-r²	8.989
x²-y²	-2.500
xy	8.038
xz	0.000
yz	0.000

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

	x	y	z
x	8.314	-0.020	0.000
y	-0.020	7.613	0.000
z	0.000	0.000	5.420

<r²> (average value of r²) Å²

<r²>	161.359
(<r²>)^1/2	12.703

Conformer 2 (C2)

Jump to S1C1 S1C3

Energy calculated at HF/Def2TZVPP

	hartrees
Energy at 0K	-304.813911
Energy at 298.15K	-304.820358
HF Energy	-304.813911
Nuclear repulsion energy	228.241181

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 HF/Def2TZVPP

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A	3286	2978	0.00
2	A	3246	2942	16.05
3	A	3186	2888	0.00
4	A	2005	1818	0.00
5	A	1584	1436	17.82
6	A	1577	1430	0.00
7	A	1535	1391	0.00
8	A	1407	1275	0.00
9	A	1107	1004	0.00
10	A	1062	962	4.23
11	A	743	673	0.00
12	A	572	518	0.00
13	A	395	358	12.58
14	A	386	350	0.00
15	A	142	129	0.11
16	A	51	46	12.99
17	B	3286	2979	23.16
18	B	3246	2942	0.00
19	B	3186	2888	4.30
20	B	1982	1797	380.00
21	B	1587	1439	0.00
22	B	1577	1430	27.34
23	B	1524	1381	37.80
24	B	1229	1114	82.83
25	B	1184	1073	0.00
26	B	982	890	20.73
27	B	682	618	0.00
28	B	589	534	58.83
29	B	255	232	18.52
30	B	144	130	0.00

Unscaled Zero Point Vibrational Energy (zpe) 21868.1 cm^-1
Scaled (by 0.9064) Zero Point Vibrational Energy (zpe) 19821.2 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 HF/Def2TZVPP

A	B	C
0.18255	0.11278	0.07152

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

Geometric Data calculated at HF/Def2TZVPP

Point Group is C₂

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.075	0.769	-0.023
C2	0.075	-0.769	-0.023
C3	1.167	1.604	0.059
C4	-1.167	-1.604	0.059
O5	-1.167	1.224	-0.067
O6	1.167	-1.224	-0.067
H7	1.027	2.528	-0.484
H8	-1.027	-2.528	-0.484
H9	1.338	1.850	1.103
H10	2.020	1.056	-0.301
H11	-1.338	-1.850	1.103
H12	-2.020	-1.056	-0.301

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5458	1.4990	2.6137	1.1828	2.3487	2.1265	3.4628	2.1063	2.1333	3.1186	2.6816
C2	1.5458		2.6137	1.4990	2.3487	1.1828	3.4628	2.1265	3.1186	2.6816	2.1063	2.1333
C3	1.4990	2.6137		3.9674	2.3673	2.8310	1.0806	4.7102	1.0865	1.0762	4.3933	4.1669
C4	2.6137	1.4990	3.9674		2.8310	2.3673	4.7102	1.0806	4.3933	4.1669	1.0865	1.0762
O5	1.1828	2.3487	2.3673	2.8310		3.3814	2.5860	3.7778	2.8348	3.1996	3.2937	2.4458
O6	2.3487	1.1828	2.8310	2.3673	3.3814		3.7778	2.5860	3.2937	2.4458	2.8348	3.1996
H7	2.1265	3.4628	1.0806	4.7102	2.5860	3.7778		5.4578	1.7536	1.7852	5.2237	4.7082
H8	3.4628	2.1265	4.7102	1.0806	3.7778	2.5860	5.4578		5.2237	4.7082	1.7536	1.7852
H9	2.1063	3.1186	1.0865	4.3933	2.8348	3.2937	1.7536	5.2237		1.7510	4.5675	4.6583
H10	2.1333	2.6816	1.0762	4.1669	3.1996	2.4458	1.7852	4.7082	1.7510		4.6583	4.5591
H11	3.1186	2.1063	4.3933	1.0865	3.2937	2.8348	5.2237	1.7536	4.5675	4.6583		1.7510
H12	2.6816	2.1333	4.1669	1.0762	2.4458	3.1996	4.7082	1.7852	4.6583	4.5591	1.7510

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	118.268	C1	C2	O6	118.202
C1	C3	H7	109.989	C1	C3	H9	108.046
C1	C3	H10	110.797	C2	C1	C3	118.268
C2	C1	O5	118.202	C2	C4	H8	109.989
C2	C4	H11	108.046	C2	C4	H12	110.797
C3	C1	O5	123.518	C4	C2	O6	123.518
H7	C3	H9	108.035	H7	C3	H10	111.722
H8	C4	H11	108.035	H8	C4	H12	111.722
H9	C3	H10	108.123	H11	C4	H12	108.123

Electronic energy levels

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

Number	Element	Mulliken
1	C	0.287
2	C	0.287
3	C	-0.161
4	C	-0.161
5	O	-0.392
6	O	-0.392
7	H	0.108
8	H	0.108
9	H	0.079
10	H	0.079
11	H	0.079
12	H	0.079

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	-39.370	8.047	0.000
y	8.047	-36.878	0.000
z	0.000	0.000	-33.632

Traceless
	x	y	z
x	-4.115	8.047	0.000
y	8.047	-0.377	0.000
z	0.000	0.000	4.491

Polar
3z²-r²	8.983
x²-y²	-2.492
xy	8.047
xz	0.000
yz	0.000

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

	x	y	z
x	8.315	-0.022	0.000
y	-0.022	7.610	0.000
z	0.000	0.000	5.420

<r²> (average value of r²) Å²

<r²>	161.323
(<r²>)^1/2	12.701

Conformer 3 (CI)

Jump to S1C1 S1C2

Energy calculated at HF/Def2TZVPP

	hartrees
Energy at 0K	-304.813911
Energy at 298.15K	-304.820359
HF Energy	-304.813911
Nuclear repulsion energy	228.239252

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 HF/Def2TZVPP

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3286	2978	0.00
2	A_g	3246	2942	0.00
3	A_g	3186	2888	0.00
4	A_g	2005	1818	0.00
5	A_g	1588	1439	0.00
6	A_g	1577	1430	0.00
7	A_g	1535	1391	0.00
8	A_g	1407	1275	0.00
9	A_g	1184	1073	0.00
10	A_g	1107	1004	0.00
11	A_g	743	673	0.00
12	A_g	682	618	0.00
13	A_g	572	518	0.00
14	A_g	386	350	0.00
15	A_g	144	130	0.00
16	A_u	3286	2979	23.16
17	A_u	3246	2942	16.05
18	A_u	3186	2888	4.32
19	A_u	1982	1797	379.85
20	A_u	1584	1436	17.81
21	A_u	1577	1430	27.34
22	A_u	1524	1381	37.75
23	A_u	1228	1114	82.81
24	A_u	1062	962	4.22
25	A_u	982	890	20.77
26	A_u	589	534	58.82
27	A_u	395	358	12.58
28	A_u	255	232	18.52
29	A_u	142	129	0.11
30	A_u	51	46	13.00

Unscaled Zero Point Vibrational Energy (zpe) 21868.2 cm^-1
Scaled (by 0.9064) Zero Point Vibrational Energy (zpe) 19821.4 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 HF/Def2TZVPP

A	B	C
0.18256	0.11277	0.07151

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

Geometric Data calculated at HF/Def2TZVPP

Point Group is C_i

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	0.021	0.000	-0.770
C2	-0.021	-0.000	0.770
C3	1.364	-0.000	-1.429
C4	-1.364	0.000	1.429
O5	-1.005	-0.000	-1.363
O6	1.005	0.000	1.363
H7	1.930	0.865	-1.108
H8	-1.930	-0.865	1.108
H9	1.930	-0.865	-1.107
H10	1.253	-0.000	-2.501
H11	-1.930	0.865	1.107
H12	-1.253	0.000	2.501

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5415	1.4955	2.5992	1.1854	2.3495	2.1225	2.8429	2.1225	2.1241	2.8427	3.5107
C2	1.5415		2.5992	1.4955	2.3495	1.1854	2.8429	2.1225	2.8427	3.5107	2.1225	2.1241
C3	1.4955	2.5992		3.9507	2.3703	2.8149	1.0824	4.2464	1.0824	1.0776	4.2463	4.7214
C4	2.5992	1.4955	3.9507		2.8149	2.3703	4.2464	1.0824	4.2463	4.7214	1.0824	1.0776
O5	1.1854	2.3495	2.3703	2.8149		3.3875	3.0709	2.7761	3.0710	2.5290	2.7757	3.8718
O6	2.3495	1.1854	2.8149	2.3703	3.3875		2.7761	3.0709	2.7757	3.8718	3.0710	2.5290
H7	2.1225	2.8429	1.0824	4.2464	3.0709	2.7761		4.7748	1.7293	1.7741	4.4505	4.8888
H8	2.8429	2.1225	4.2464	1.0824	2.7761	3.0709	4.7748		4.4505	4.8888	1.7293	1.7741
H9	2.1225	2.8427	1.0824	4.2463	3.0710	2.7757	1.7293	4.4505		1.7741	4.7745	4.8887
H10	2.1241	3.5107	1.0776	4.7214	2.5290	3.8718	1.7741	4.8888	1.7741		4.8887	5.5944
H11	2.8427	2.1225	4.2463	1.0824	2.7757	3.0710	4.4505	1.7293	4.7745	4.8887		1.7741
H12	3.5107	2.1241	4.7214	1.0776	3.8718	2.5290	4.8888	1.7741	4.8887	5.5944	1.7741

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	117.703	C1	C2	O6	118.415
C1	C3	H7	109.808	C1	C3	H9	109.807
C1	C3	H10	110.225	C2	C1	C3	117.703
C2	C1	O5	118.415	C2	C4	H8	109.808
C2	C4	H11	109.807	C2	C4	H12	110.225
C3	C1	O5	123.882	C4	C2	O6	123.882
H7	C3	H9	106.033	H7	C3	H10	110.442
H8	C4	H11	106.033	H8	C4	H12	110.442
H9	C3	H10	110.442	H11	C4	H12	110.442

Electronic energy levels

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

Number	Element	Mulliken
1	C	0.287
2	C	0.287
3	C	-0.161
4	C	-0.161
5	O	-0.392
6	O	-0.392
7	H	0.079
8	H	0.079
9	H	0.079
10	H	0.108
11	H	0.079
12	H	0.108

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	-37.283	-0.001	-8.099
y	-0.001	-33.632	-0.000
z	-8.099	-0.000	-38.966

Traceless
	x	y	z
x	-0.984	-0.001	-8.099
y	-0.001	4.493	-0.000
z	-8.099	-0.000	-3.509

Polar
3z²-r²	-7.018
x²-y²	-3.651
xy	-0.001
xz	-8.099
yz	-0.000

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

	x	y	z
x	8.298	0.000	0.111
y	0.000	5.420	0.000
z	0.111	0.000	7.628

<r²> (average value of r²) Å²

<r²>	161.328
(<r²>)^1/2	12.702

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

using model chemistry: HF/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: HF/Def2TZVPP

States and conformations

Conformer 1 (C2H)

Conformer 2 (C2)

Conformer 3 (CI)

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