CCCBDB calculation results Page

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

Conformer 1 (C2H)

Jump to S1C2 S1C3

Energy calculated at LSDA/6-31G(2df,p)

	hartrees
Energy at 0K	-304.873384
Energy at 298.15K
Nuclear repulsion energy	227.764267

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 LSDA/6-31G(2df,p)

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3125	3075	0.00
2	A_g	2990	2943	0.00
3	A_g	1791	1763	0.00
4	A_g	1365	1343	0.00
5	A_g	1339	1318	0.00
6	A_g	1252	1232	0.00
7	A_g	961	946	0.00
8	A_g	696	685	0.00
9	A_g	518	509	0.00
10	A_g	351	346	0.00
11	A_u	3061	3012	0.44
12	A_u	1364	1342	26.26
13	A_u	882	868	9.35
14	A_u	332	326	2.25
15	A_u	100	99	1.76
16	A_u	34i	33i	9.64
17	B_g	3062	3013	0.00
18	B_g	1372	1350	0.00
19	B_g	1021	1005	0.00
20	B_g	603	593	0.00
21	B_g	51	51	0.00
22	B_u	3125	3075	4.50
23	B_u	2990	2943	2.91
24	B_u	1802	1773	210.75
25	B_u	1364	1342	30.66
26	B_u	1303	1282	134.30
27	B_u	1111	1093	73.41
28	B_u	891	877	9.40
29	B_u	514	506	34.55
30	B_u	232	228	18.10

Unscaled Zero Point Vibrational Energy (zpe) 19767.0 cm^-1
Scaled (by 0.984) Zero Point Vibrational Energy (zpe) 19450.8 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 LSDA/6-31G(2df,p)

A	B	C
0.17605	0.11695	0.07212

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

Geometric Data calculated at LSDA/6-31G(2df,p)

Point Group is C_2h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.079	0.760	0.000
C2	0.079	-0.760	0.000
C3	1.190	1.529	0.000
C4	-1.190	-1.529	0.000
O5	-1.190	1.243	0.000
O6	1.190	-1.243	0.000
H7	0.988	2.608	0.000
H8	-0.988	-2.608	0.000
H9	1.799	1.240	0.873
H10	1.799	1.240	-0.873
H11	-1.799	-1.240	0.873
H12	-1.799	-1.240	-0.873

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5285	1.4836	2.5443	1.2114	2.3714	2.1334	3.4883	2.1264	2.1264	2.7789	2.7789
C2	1.5285		2.5443	1.4836	2.3714	1.2114	3.4883	2.1334	2.7789	2.7789	2.1264	2.1264
C3	1.4836	2.5443		3.8746	2.3970	2.7719	1.0977	4.6747	1.1036	1.1036	4.1670	4.1670
C4	2.5443	1.4836	3.8746		2.7719	2.3970	4.6747	1.0977	4.1670	4.1670	1.1036	1.1036
O5	1.2114	2.3714	2.3970	2.7719		3.4417	2.5700	3.8561	3.1143	3.1143	2.7016	2.7016
O6	2.3714	1.2114	2.7719	2.3970	3.4417		3.8561	2.5700	2.7016	2.7016	3.1143	3.1143
H7	2.1334	3.4883	1.0977	4.6747	2.5700	3.8561		5.5770	1.8146	1.8146	4.8305	4.8305
H8	3.4883	2.1334	4.6747	1.0977	3.8561	2.5700	5.5770		4.8305	4.8305	1.8146	1.8146
H9	2.1264	2.7789	1.1036	4.1670	3.1143	2.7016	1.8146	4.8305		1.7470	4.3702	4.7065
H10	2.1264	2.7789	1.1036	4.1670	3.1143	2.7016	1.8146	4.8305	1.7470		4.7065	4.3702
H11	2.7789	2.1264	4.1670	1.1036	2.7016	3.1143	4.8305	1.8146	4.3702	4.7065		1.7470
H12	2.7789	2.1264	4.1670	1.1036	2.7016	3.1143	4.8305	1.8146	4.7065	4.3702	1.7470

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	115.267	C1	C2	O6	119.433
C1	C3	H7	110.592	C1	C3	H9	109.673
C1	C3	H10	109.673	C2	C1	C3	115.267
C2	C1	O5	119.433	C2	C4	H8	110.592
C2	C4	H11	109.673	C2	C4	H12	109.673
C3	C1	O5	125.300	C4	C2	O6	125.300
H7	C3	H9	111.047	H7	C3	H10	111.047
H8	C4	H11	111.047	H8	C4	H12	111.047
H9	C3	H10	104.647	H11	C4	H12	104.647

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at LSDA/6-31G(2df,p) Charges (e)

Number	Element	Mulliken
1	C	0.256
2	C	0.256
3	C	-0.593
4	C	-0.593
5	O	-0.226
6	O	-0.226
7	H	0.173
8	H	0.173
9	H	0.195
10	H	0.195
11	H	0.195
12	H	0.195

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	-37.254	6.856	0.000
y	6.856	-35.880	0.000
z	0.000	0.000	-33.060

Traceless
	x	y	z
x	-2.785	6.856	0.000
y	6.856	-0.723	0.000
z	0.000	0.000	3.507

Polar
3z²-r²	7.014
x²-y²	-1.375
xy	6.856
xz	0.000
yz	0.000

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

	x	y	z
x	8.481	0.332	0.000
y	0.332	7.917	0.000
z	0.000	0.000	5.086

<r²> (average value of r²) Å²

<r²>	159.239
(<r²>)^1/2	12.619

Conformer 2 (C2)

Jump to S1C1 S1C3

Energy calculated at LSDA/6-31G(2df,p)

	hartrees
Energy at 0K	-304.873433
Energy at 298.15K	-304.879262
Nuclear repulsion energy	227.729231

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 LSDA/6-31G(2df,p)

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A	3126	3076	0.09
2	A	3062	3013	0.32
3	A	2986	2938	0.02
4	A	1791	1762	1.98
5	A	1378	1356	0.98
6	A	1357	1335	23.92
7	A	1332	1310	4.93
8	A	1245	1225	0.00
9	A	961	946	0.01
10	A	883	869	10.42
11	A	693	682	0.14
12	A	522	514	0.16
13	A	359	354	0.59
14	A	324	319	1.79
15	A	101	100	0.93
16	A	49	48	9.71
17	B	3126	3076	1.32
18	B	3062	3013	2.48
19	B	2985	2938	2.62
20	B	1801	1772	206.78
21	B	1376	1354	27.02
22	B	1365	1343	10.08
23	B	1299	1278	138.47
24	B	1107	1089	74.85
25	B	1020	1004	2.04
26	B	899	884	5.21
27	B	601	591	0.56
28	B	512	504	30.76
29	B	245	241	18.51
30	B	86	85	0.75

Unscaled Zero Point Vibrational Energy (zpe) 19826.3 cm^-1
Scaled (by 0.984) Zero Point Vibrational Energy (zpe) 19509.1 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 LSDA/6-31G(2df,p)

A	B	C
0.17590	0.11646	0.07226

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

Geometric Data calculated at LSDA/6-31G(2df,p)

Point Group is C₂

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.079	0.761	-0.015
C2	0.079	-0.761	-0.015
C3	1.187	1.527	0.081
C4	-1.187	-1.527	0.081
O5	-1.187	1.245	-0.099
O6	1.187	-1.245	-0.099
H7	1.024	2.583	-0.174
H8	-1.024	-2.583	-0.174
H9	1.570	1.457	1.116
H10	1.960	1.053	-0.545
H11	-1.570	-1.457	1.116
H12	-1.960	-1.053	-0.545

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5311	1.4832	2.5446	1.2114	2.3740	2.1356	3.4786	2.1174	2.1270	2.9021	2.6663
C2	1.5311		2.5446	1.4832	2.3740	1.2114	3.4786	2.1356	2.9021	2.6663	2.1174	2.1270
C3	1.4832	2.5446		3.8690	2.3977	2.7781	1.0978	4.6742	1.1056	1.1018	4.1929	4.1175
C4	2.5446	1.4832	3.8690		2.7781	2.3977	4.6742	1.0978	4.1929	4.1175	1.1056	1.1018
O5	1.2114	2.3740	2.3977	2.7781		3.4400	2.5857	3.8316	3.0207	3.1839	2.9873	2.4648
O6	2.3740	1.2114	2.7781	2.3977	3.4400		3.8316	2.5857	2.9873	2.4648	3.0207	3.1839
H7	2.1356	3.4786	1.0978	4.6742	2.5857	3.8316		5.5567	1.7971	1.8308	4.9715	4.7181
H8	3.4786	2.1356	4.6742	1.0978	3.8316	2.5857	5.5567		4.9715	4.7181	1.7971	1.8308
H9	2.1174	2.9021	1.1056	4.1929	3.0207	2.9873	1.7971	4.9715		1.7529	4.2841	4.6388
H10	2.1270	2.6663	1.1018	4.1175	3.1839	2.4648	1.8308	4.7181	1.7529		4.6388	4.4496
H11	2.9021	2.1174	4.1929	1.1056	2.9873	3.0207	4.9715	1.7971	4.2841	4.6388		1.7529
H12	2.6663	2.1270	4.1175	1.1018	2.4648	3.1839	4.7181	1.8308	4.6388	4.4496	1.7529

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	115.158	C1	C2	O6	119.451
C1	C3	H7	110.781	C1	C3	H9	108.877
C1	C3	H10	109.859	C2	C1	C3	115.158
C2	C1	O5	119.451	C2	C4	H8	110.781
C2	C4	H11	108.877	C2	C4	H12	109.859
C3	C1	O5	125.389	C4	C2	O6	125.389
H7	C3	H9	109.294	H7	C3	H10	112.679
H8	C4	H11	109.294	H8	C4	H12	112.679
H9	C3	H10	105.142	H11	C4	H12	105.142

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at LSDA/6-31G(2df,p) Charges (e)

Number	Element	Mulliken
1	C	0.257
2	C	0.257
3	C	-0.593
4	C	-0.593
5	O	-0.229
6	O	-0.229
7	H	0.176
8	H	0.176
9	H	0.194
10	H	0.196
11	H	0.194
12	H	0.196

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	0.522	0.522
CHELPG
AIM
ESP

Electric Quadrupole moment
Quadrupole components in D Å

Primitive
	x	y	z
x	-37.415	6.814	0.000
y	6.814	-35.719	0.000
z	0.000	0.000	-33.071

Traceless
	x	y	z
x	-3.020	6.814	0.000
y	6.814	-0.475	0.000
z	0.000	0.000	3.496

Polar
3z²-r²	6.991
x²-y²	-1.697
xy	6.814
xz	0.000
yz	0.000

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

	x	y	z
x	8.408	0.411	0.000
y	0.411	7.995	0.000
z	0.000	0.000	5.142

<r²> (average value of r²) Å²

<r²>	159.285
(<r²>)^1/2	12.621

Conformer 3 (CI)

Jump to S1C1 S1C2

Energy calculated at LSDA/6-31G(2df,p)

	hartrees
Energy at 0K	-304.873383
Energy at 298.15K
Nuclear repulsion energy	227.761262

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 LSDA/6-31G(2df,p)

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3125	3075	0.00
2	A_g	3061	3013	0.00
3	A_g	2990	2942	0.00
4	A_g	1792	1763	0.00
5	A_g	1370	1348	0.00
6	A_g	1365	1344	0.00
7	A_g	1338	1316	0.00
8	A_g	1251	1231	0.00
9	A_g	1021	1004	0.00
10	A_g	960	945	0.00
11	A_g	696	685	0.00
12	A_g	600	590	0.00
13	A_g	517	509	0.00
14	A_g	350	345	0.00
15	A_g	44	44	0.00
16	A_u	3126	3076	4.47
17	A_u	3061	3012	0.43
18	A_u	2990	2942	2.89
19	A_u	1802	1773	210.77
20	A_u	1364	1342	30.82
21	A_u	1362	1341	26.36
22	A_u	1299	1278	134.31
23	A_u	1111	1093	74.21
24	A_u	890	876	9.00
25	A_u	881	867	9.29
26	A_u	514	506	34.33
27	A_u	329	323	2.26
28	A_u	232	228	18.06
29	A_u	97	95	1.80
30	A_u	38i	37i	9.57

Unscaled Zero Point Vibrational Energy (zpe) 19749.8 cm^-1
Scaled (by 0.984) Zero Point Vibrational Energy (zpe) 19433.8 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 LSDA/6-31G(2df,p)

A	B	C
0.17601	0.11696	0.07212

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

Geometric Data calculated at LSDA/6-31G(2df,p)

Point Group is C_i

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	-0.764
C2	0.000	0.000	0.764
C3	1.342	0.000	-1.397
C4	-1.342	0.000	1.397
O5	-1.055	0.000	-1.360
O6	1.055	0.000	1.360
H7	1.918	0.873	-1.046
H8	-1.918	-0.873	1.046
H9	1.918	-0.873	-1.046
H10	1.253	-0.000	-2.491
H11	-1.918	0.873	1.046
H12	-1.253	0.000	2.491

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5288	1.4837	2.5442	1.2113	2.3717	2.1263	2.7784	2.1263	2.1334	2.7783	3.4883
C2	1.5288		2.5442	1.4837	2.3717	1.2113	2.7784	2.1263	2.7783	3.4883	2.1263	2.1334
C3	1.4837	2.5442		3.8744	2.3971	2.7719	1.1036	4.1665	1.1036	1.0976	4.1665	4.6746
C4	2.5442	1.4837	3.8744		2.7719	2.3971	4.1665	1.1036	4.1665	4.6746	1.1036	1.0976
O5	1.2113	2.3717	2.3971	2.7719		3.4420	3.1144	2.7012	3.1144	2.5702	2.7011	3.8561
O6	2.3717	1.2113	2.7719	2.3971	3.4420		2.7012	3.1144	2.7011	3.8561	3.1144	2.5702
H7	2.1263	2.7784	1.1036	4.1665	3.1144	2.7012		4.7058	1.7467	1.8148	4.3696	4.8301
H8	2.7784	2.1263	4.1665	1.1036	2.7012	3.1144	4.7058		4.3696	4.8301	1.7467	1.8148
H9	2.1263	2.7783	1.1036	4.1665	3.1144	2.7011	1.7467	4.3696		1.8148	4.7057	4.8301
H10	2.1334	3.4883	1.0976	4.6746	2.5702	3.8561	1.8148	4.8301	1.8148		4.8301	5.5770
H11	2.7783	2.1263	4.1665	1.1036	2.7011	3.1144	4.3696	1.7467	4.7057	4.8301		1.8148
H12	3.4883	2.1334	4.6746	1.0976	3.8561	2.5702	4.8301	1.8148	4.8301	5.5770	1.8148

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	115.243	C1	C2	O6	119.446
C1	C3	H7	109.666	C1	C3	H9	109.665
C1	C3	H10	110.593	C2	C1	C3	115.243
C2	C1	O5	119.446	C2	C4	H8	109.666
C2	C4	H11	109.665	C2	C4	H12	110.593
C3	C1	O5	125.311	C4	C2	O6	125.311
H7	C3	H9	104.625	H7	C3	H10	111.064
H8	C4	H11	104.625	H8	C4	H12	111.064
H9	C3	H10	111.065	H11	C4	H12	111.065

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at LSDA/6-31G(2df,p) Charges (e)

Number	Element	Mulliken
1	C	0.256
2	C	0.256
3	C	-0.593
4	C	-0.593
5	O	-0.226
6	O	-0.226
7	H	0.195
8	H	0.195
9	H	0.195
10	H	0.173
11	H	0.195
12	H	0.173

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	-35.827	0.000	-6.848
y	0.000	-33.061	-0.000
z	-6.848	-0.000	-37.310

Traceless
	x	y	z
x	-0.641	0.000	-6.848
y	0.000	3.507	-0.000
z	-6.848	-0.000	-2.866

Polar
3z²-r²	-5.732
x²-y²	-2.766
xy	0.000
xz	-6.848
yz	-0.000

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

	x	y	z
x	8.544	0.000	-0.266
y	0.000	5.085	0.000
z	-0.266	0.000	7.855

<r²> (average value of r²) Å²

<r²>	159.241
(<r²>)^1/2	12.619

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

using model chemistry: LSDA/6-31G(2df,p)

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: LSDA/6-31G(2df,p)

States and conformations

Conformer 1 (C2H)

Conformer 2 (C2)

Conformer 3 (CI)

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