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 BLYP/6-31G*

	hartrees
Energy at 0K	-306.375297
Energy at 298.15K	-306.381142
HF Energy	-306.375297
Nuclear repulsion energy	223.273559

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 BLYP/6-31G*

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3093	3068	0.00
2	A_g	2985	2961	0.00
3	A_g	1711	1697	0.00
4	A_g	1448	1436	0.00
5	A_g	1371	1360	0.00
6	A_g	1232	1222	0.00
7	A_g	988	980	0.00
8	A_g	653	648	0.00
9	A_g	499	495	0.00
10	A_g	352	349	0.00
11	A_u	3037	3012	8.99
12	A_u	1451	1439	16.67
13	A_u	939	931	5.75
14	A_u	331	328	3.58
15	A_u	109	108	0.01
16	A_u	55	54	9.46
17	B_g	3037	3012	0.00
18	B_g	1456	1444	0.00
19	B_g	1041	1033	0.00
20	B_g	604	599	0.00
21	B_g	105	104	0.00
22	B_u	3093	3068	19.82
23	B_u	2985	2961	0.71
24	B_u	1718	1704	180.76
25	B_u	1449	1438	26.20
26	B_u	1368	1357	56.87
27	B_u	1106	1097	85.73
28	B_u	878	871	30.79
29	B_u	524	520	34.93
30	B_u	233	231	15.09

Unscaled Zero Point Vibrational Energy (zpe) 19925.3 cm^-1
Scaled (by 0.9919) Zero Point Vibrational Energy (zpe) 19763.9 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 BLYP/6-31G*

A	B	C
0.17198	0.10985	0.06875

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

Geometric Data calculated at BLYP/6-31G*

Point Group is C_2h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.052	0.749	0.000
C2	0.052	-0.749	0.000
C3	1.198	1.590	0.000
C4	-1.198	-1.590	0.000
O5	-1.198	1.255	0.000
O6	1.198	-1.255	0.000
H7	0.923	2.652	0.000
H8	-0.923	-2.652	0.000
H9	1.817	1.365	0.884
H10	1.817	1.365	-0.884
H11	-1.817	-1.365	0.884
H12	-1.817	-1.365	-0.884

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5021	1.5061	2.6047	1.2526	2.3618	2.1377	3.5108	2.1568	2.1568	2.8926	2.8926
C2	1.5021		2.6047	1.5061	2.3618	1.2526	3.5108	2.1377	2.8926	2.8926	2.1568	2.1568
C3	1.5061	2.6047		3.9811	2.4191	2.8446	1.0968	4.7423	1.1020	1.1020	4.3129	4.3129
C4	2.6047	1.5061	3.9811		2.8446	2.4191	4.7423	1.0968	4.3129	4.3129	1.1020	1.1020
O5	1.2526	2.3618	2.4191	2.8446		3.4696	2.5399	3.9161	3.1434	3.1434	2.8335	2.8335
O6	2.3618	1.2526	2.8446	2.4191	3.4696		3.9161	2.5399	2.8335	2.8335	3.1434	3.1434
H7	2.1377	3.5108	1.0968	4.7423	2.5399	3.9161		5.6156	1.7983	1.7983	4.9421	4.9421
H8	3.5108	2.1377	4.7423	1.0968	3.9161	2.5399	5.6156		4.9421	4.9421	1.7983	1.7983
H9	2.1568	2.8926	1.1020	4.3129	3.1434	2.8335	1.7983	4.9421		1.7678	4.5450	4.8767
H10	2.1568	2.8926	1.1020	4.3129	3.1434	2.8335	1.7983	4.9421	1.7678		4.8767	4.5450
H11	2.8926	2.1568	4.3129	1.1020	2.8335	3.1434	4.9421	1.7983	4.5450	4.8767		1.7678
H12	2.8926	2.1568	4.3129	1.1020	2.8335	3.1434	4.9421	1.7983	4.8767	4.5450	1.7678

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	119.966	C1	C2	O6	117.759
C1	C3	H7	109.425	C1	C3	H9	110.621
C1	C3	H10	110.621	C2	C1	C3	119.966
C2	C1	O5	117.759	C2	C4	H8	109.425
C2	C4	H11	110.621	C2	C4	H12	110.621
C3	C1	O5	122.275	C4	C2	O6	122.275
H7	C3	H9	109.741	H7	C3	H10	109.741
H8	C4	H11	109.741	H8	C4	H12	109.741
H9	C3	H10	106.654	H11	C4	H12	106.654

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at BLYP/6-31G* Charges (e)

Number	Element	Mulliken
1	C	0.371
2	C	0.371
3	C	-0.482
4	C	-0.482
5	O	-0.394
6	O	-0.394
7	H	0.161
8	H	0.161
9	H	0.172
10	H	0.172
11	H	0.172
12	H	0.172

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	-37.898	6.895	0.000
y	6.895	-36.343	0.000
z	0.000	0.000	-33.249

Traceless
	x	y	z
x	-3.102	6.895	0.000
y	6.895	-0.770	0.000
z	0.000	0.000	3.872

Polar
3z²-r²	7.743
x²-y²	-1.555
xy	6.895
xz	0.000
yz	0.000

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

	x	y	z
x	8.278	0.150	0.000
y	0.150	7.678	0.000
z	0.000	0.000	4.746

<r²> (average value of r²) Å²

<r²>	166.162
(<r²>)^1/2	12.890

Conformer 2 (C2)

Jump to S1C1 S1C3

Energy calculated at BLYP/6-31G*

	hartrees
Energy at 0K	-306.375297
Energy at 298.15K	-306.381140
HF Energy	-306.375297
Nuclear repulsion energy	223.296449

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 BLYP/6-31G*

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A	3093	3068	0.00
2	A	3036	3012	8.97
3	A	2985	2960	0.00
4	A	1711	1698	0.00
5	A	1451	1439	16.71
6	A	1448	1436	0.00
7	A	1372	1361	0.00
8	A	1233	1223	0.00
9	A	989	981	0.00
10	A	939	931	5.76
11	A	654	648	0.00
12	A	499	495	0.00
13	A	352	349	0.00
14	A	331	328	3.57
15	A	109	108	0.01
16	A	54	54	9.47
17	B	3093	3068	19.81
18	B	3036	3012	0.00
19	B	2985	2960	0.70
20	B	1718	1704	180.85
21	B	1456	1444	0.00
22	B	1450	1438	26.25
23	B	1369	1358	57.23
24	B	1107	1098	85.86
25	B	1041	1033	0.00
26	B	880	873	30.30
27	B	604	599	0.00
28	B	525	520	35.05
29	B	233	231	15.08
30	B	105	104	0.00

Unscaled Zero Point Vibrational Energy (zpe) 19926.2 cm^-1
Scaled (by 0.9919) Zero Point Vibrational Energy (zpe) 19764.8 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 BLYP/6-31G*

A	B	C
0.17203	0.10987	0.06876

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

Geometric Data calculated at BLYP/6-31G*

Point Group is C₂

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	0.086	0.780	0.000
C2	-0.086	-0.780	0.000
C3	-1.206	1.593	0.000
C4	1.206	-1.593	0.000
O5	1.206	1.274	-0.000
O6	-1.206	-1.274	-0.000
H7	-0.964	2.664	0.000
H8	0.964	-2.664	0.000
H9	-1.818	1.343	-0.881
H10	-1.818	1.343	0.882
H11	1.818	-1.343	-0.881
H12	1.818	-1.343	0.882

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5699	1.5256	2.6240	1.2237	2.4263	2.1562	3.5542	2.1724	2.1724	2.8787	2.8789
C2	1.5699		2.6240	1.5256	2.4263	1.2237	3.5542	2.1562	2.8787	2.8789	2.1724	2.1724
C3	1.5256	2.6240		3.9952	2.4321	2.8666	1.0980	4.7775	1.1023	1.1023	4.3059	4.3058
C4	2.6240	1.5256	3.9952		2.8666	2.4321	4.7775	1.0980	4.3059	4.3058	1.1023	1.1023
O5	1.2237	2.4263	2.4321	2.8666		3.5077	2.5763	3.9451	3.1504	3.1504	2.8283	2.8290
O6	2.4263	1.2237	2.8666	2.4321	3.5077		3.9451	2.5763	2.8283	2.8290	3.1504	3.1504
H7	2.1562	3.5542	1.0980	4.7775	2.5763	3.9451		5.6655	1.8033	1.8033	4.9570	4.9570
H8	3.5542	2.1562	4.7775	1.0980	3.9451	2.5763	5.6655		4.9570	4.9570	1.8033	1.8033
H9	2.1724	2.8787	1.1023	4.3059	3.1504	2.8283	1.8033	4.9570		1.7633	4.5213	4.8527
H10	2.1724	2.8789	1.1023	4.3058	3.1504	2.8290	1.8033	4.9570	1.7633		4.8527	4.5208
H11	2.8787	2.1724	4.3059	1.1023	2.8283	3.1504	4.9570	1.8033	4.5213	4.8527		1.7633
H12	2.8789	2.1724	4.3058	1.1023	2.8290	3.1504	4.9570	1.8033	4.8527	4.5208	1.7633

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	115.909	C1	C2	O6	120.058
C1	C3	H7	109.454	C1	C3	H9	110.476
C1	C3	H10	110.477	C2	C1	C3	115.909
C2	C1	O5	120.058	C2	C4	H8	109.454
C2	C4	H11	110.476	C2	C4	H12	110.477
C3	C1	O5	124.033	C4	C2	O6	124.033
H7	C3	H9	110.082	H7	C3	H10	110.085
H8	C4	H11	110.082	H8	C4	H12	110.085
H9	C3	H10	106.228	H11	C4	H12	106.228

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at BLYP/6-31G* Charges (e)

Number	Element	Mulliken
1	C	0.371
2	C	0.371
3	C	-0.482
4	C	-0.482
5	O	-0.394
6	O	-0.394
7	H	0.161
8	H	0.161
9	H	0.172
10	H	0.172
11	H	0.172
12	H	0.172

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	-37.893	-6.902	0.000
y	-6.902	-36.341	0.000
z	0.000	0.000	-33.250

Traceless
	x	y	z
x	-3.097	-6.902	0.000
y	-6.902	-0.770	0.000
z	0.000	0.000	3.867

Polar
3z²-r²	7.734
x²-y²	-1.552
xy	-6.902
xz	0.000
yz	0.000

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

	x	y	z
x	8.277	-0.149	0.000
y	-0.149	7.677	0.000
z	0.000	0.000	4.745

<r²> (average value of r²) Å²

<r²>	166.128
(<r²>)^1/2	12.889

Conformer 3 (CI)

Jump to S1C1 S1C2

Energy calculated at BLYP/6-31G*

	hartrees
Energy at 0K	-306.375291
Energy at 298.15K	-306.381109
HF Energy	-306.375291
Nuclear repulsion energy	223.278004

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 BLYP/6-31G*

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3092	3067	0.00
2	A_g	3036	3011	0.00
3	A_g	2984	2960	0.00
4	A_g	1712	1698	0.00
5	A_g	1454	1443	0.00
6	A_g	1448	1436	0.00
7	A_g	1369	1358	0.00
8	A_g	1232	1222	0.00
9	A_g	1040	1032	0.00
10	A_g	988	980	0.00
11	A_g	652	647	0.00
12	A_g	602	597	0.00
13	A_g	498	494	0.00
14	A_g	351	348	0.00
15	A_g	102	101	0.00
16	A_u	3093	3068	19.84
17	A_u	3036	3011	8.99
18	A_u	2984	2960	0.71
19	A_u	1718	1705	181.08
20	A_u	1450	1438	16.75
21	A_u	1449	1438	26.33
22	A_u	1366	1355	56.61
23	A_u	1106	1097	86.91
24	A_u	937	930	5.73
25	A_u	879	872	30.11
26	A_u	524	520	34.93
27	A_u	328	326	3.61
28	A_u	232	230	15.06
29	A_u	105	104	0.00
30	A_u	52	52	9.43

Unscaled Zero Point Vibrational Energy (zpe) 19909.2 cm^-1
Scaled (by 0.9919) Zero Point Vibrational Energy (zpe) 19747.9 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 BLYP/6-31G*

A	B	C
0.17201	0.10984	0.06874

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

Geometric Data calculated at BLYP/6-31G*

Point Group is C_i

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.010	-0.000	-0.785
C2	0.010	0.000	0.785
C3	1.354	-0.000	-1.469
C4	-1.354	0.000	1.469
O5	-1.076	-0.000	-1.385
O6	1.076	0.000	1.385
H7	1.939	0.883	-1.162
H8	-1.939	-0.883	1.162
H9	1.941	-0.881	-1.160
H10	1.217	-0.002	-2.558
H11	-1.941	0.881	1.160
H12	-1.217	0.002	2.558

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5700	1.5257	2.6242	1.2237	2.4263	2.1724	2.8798	2.1726	2.1561	2.8787	3.5543
C2	1.5700		2.6242	1.5257	2.4263	1.2237	2.8798	2.1724	2.8787	3.5543	2.1726	2.1561
C3	1.5257	2.6242		3.9955	2.4319	2.8670	1.1023	4.3067	1.1022	1.0980	4.3060	4.7776
C4	2.6242	1.5257	3.9955		2.8670	2.4319	4.3067	1.1023	4.3060	4.7776	1.1022	1.0980
O5	1.2237	2.4263	2.4319	2.8670		3.5078	3.1498	2.8305	3.1510	2.5760	2.8281	3.9454
O6	2.4263	1.2237	2.8670	2.4319	3.5078		2.8305	3.1498	2.8281	3.9454	3.1510	2.5760
H7	2.1724	2.8798	1.1023	4.3067	3.1498	2.8305		4.8540	1.7633	1.8032	4.5217	4.9577
H8	2.8798	2.1724	4.3067	1.1023	2.8305	3.1498	4.8540		4.5217	4.9577	1.7633	1.8032
H9	2.1726	2.8787	1.1022	4.3060	3.1510	2.8281	1.7633	4.5217		1.8033	4.8527	4.9570
H10	2.1561	3.5543	1.0980	4.7776	2.5760	3.9454	1.8032	4.9577	1.8033		4.9570	5.6656
H11	2.8787	2.1726	4.3060	1.1022	2.8281	3.1510	4.5217	1.7633	4.8527	4.9570		1.8033
H12	3.5543	2.1561	4.7776	1.0980	3.9454	2.5760	4.9577	1.8032	4.9570	5.6656	1.8033

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	115.920	C1	C2	O6	120.062
C1	C3	H7	110.479	C1	C3	H9	110.491
C1	C3	H10	109.447	C2	C1	C3	115.920
C2	C1	O5	120.062	C2	C4	H8	110.479
C2	C4	H11	110.491	C2	C4	H12	109.447
C3	C1	O5	124.018	C4	C2	O6	124.018
H7	C3	H9	106.230	H7	C3	H10	110.071
H8	C4	H11	106.230	H8	C4	H12	110.071
H9	C3	H10	110.085	H11	C4	H12	110.085

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at BLYP/6-31G* Charges (e)

Number	Element	Mulliken
1	C	0.371
2	C	0.371
3	C	-0.482
4	C	-0.482
5	O	-0.394
6	O	-0.394
7	H	0.172
8	H	0.172
9	H	0.172
10	H	0.161
11	H	0.172
12	H	0.161

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	-36.585	-0.001	-6.923
y	-0.001	-33.250	-0.003
z	-6.923	-0.003	-37.651

Traceless
	x	y	z
x	-1.135	-0.001	-6.923
y	-0.001	3.868	-0.003
z	-6.923	-0.003	-2.734

Polar
3z²-r²	-5.467
x²-y²	-3.335
xy	-0.001
xz	-6.923
yz	-0.003

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

	x	y	z
x	8.299	0.001	-0.091
y	0.001	4.746	0.001
z	-0.091	0.001	7.656

<r²> (average value of r²) Å²

<r²>	166.162
(<r²>)^1/2	12.890

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

using model chemistry: BLYP/6-31G*

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: BLYP/6-31G*

States and conformations

Conformer 1 (C2H)

Conformer 2 (C2)

Conformer 3 (CI)

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