CCCBDB calculation results Page

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

Conformer 2 (C2)

Jump to S1C1 S1C3

Energy calculated at BLYP/3-21G

	hartrees
Energy at 0K	-304.687263
Energy at 298.15K
Nuclear repulsion energy	222.904071

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/3-21G

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3093	3076	0.00
2	A_g	2990	2973	0.00
3	A_g	1655	1645	0.00
4	A_g	1475	1466	0.00
5	A_g	1397	1389	0.00
6	A_g	1192	1185	0.00
7	A_g	983	978	0.00
8	A_g	629	626	0.00
9	A_g	516	513	0.00
10	A_g	361	359	0.00
11	A_u	3035	3018	6.43
12	A_u	1492	1484	24.03
13	A_u	975	970	8.48
14	A_u	368	366	0.90
15	A_u	115	114	2.72
16	A_u	42i	42i	5.86
17	B_g	3035	3018	0.00
18	B_g	1498	1490	0.00
19	B_g	1074	1068	0.00
20	B_g	655	651	0.00
21	B_g	22i	22i	0.00
22	B_u	3094	3077	18.83
23	B_u	2990	2973	0.05
24	B_u	1656	1647	97.20
25	B_u	1478	1470	32.34
26	B_u	1396	1388	86.14
27	B_u	1113	1106	88.04
28	B_u	866	861	37.45
29	B_u	514	511	25.15
30	B_u	242	240	17.47

Unscaled Zero Point Vibrational Energy (zpe) 19909.7 cm^-1
Scaled (by 0.9945) Zero Point Vibrational Energy (zpe) 19800.2 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 BLYP/3-21G

A	B	C
0.16597	0.11313	0.06901

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

Geometric Data calculated at BLYP/3-21G

Point Group is C_2h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	-0.086	0.774	0.000
C2	0.086	-0.774	0.000
C3	1.227	1.547	0.000
C4	-1.227	-1.547	0.000
O5	-1.227	1.275	0.000
O6	1.227	-1.275	0.000
H7	1.029	2.627	0.000
H8	-1.029	-2.627	0.000
H9	1.825	1.266	0.884
H10	1.825	1.266	-0.884
H11	-1.825	-1.266	0.884
H12	-1.825	-1.266	-0.884

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5582	1.5237	2.5871	1.2464	2.4339	2.1621	3.5297	2.1619	2.1619	2.8231	2.8231
C2	1.5582		2.5871	1.5237	2.4339	1.2464	3.5297	2.1621	2.8231	2.8231	2.1619	2.1619
C3	1.5237	2.5871		3.9498	2.4696	2.8222	1.0977	4.7450	1.1032	1.1032	4.2442	4.2442
C4	2.5871	1.5237	3.9498		2.8222	2.4696	4.7450	1.0977	4.2442	4.2442	1.1032	1.1032
O5	1.2464	2.4339	2.4696	2.8222		3.5392	2.6305	3.9068	3.1775	3.1775	2.7560	2.7560
O6	2.4339	1.2464	2.8222	2.4696	3.5392		3.9068	2.6305	2.7560	2.7560	3.1775	3.1775
H7	2.1621	3.5297	1.0977	4.7450	2.6305	3.9068		5.6426	1.8071	1.8071	4.9075	4.9075
H8	3.5297	2.1621	4.7450	1.0977	3.9068	2.6305	5.6426		4.9075	4.9075	1.8071	1.8071
H9	2.1619	2.8231	1.1032	4.2442	3.1775	2.7560	1.8071	4.9075		1.7676	4.4423	4.7811
H10	2.1619	2.8231	1.1032	4.2442	3.1775	2.7560	1.8071	4.9075	1.7676		4.7811	4.4423
H11	2.8231	2.1619	4.2442	1.1032	2.7560	3.1775	4.9075	1.8071	4.4423	4.7811		1.7676
H12	2.8231	2.1619	4.2442	1.1032	2.7560	3.1775	4.9075	1.8071	4.7811	4.4423	1.7676

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	114.160	C1	C2	O6	119.997
C1	C3	H7	110.081	C1	C3	H9	109.730
C1	C3	H10	109.730	C2	C1	C3	114.160
C2	C1	O5	119.997	C2	C4	H8	110.081
C2	C4	H11	109.730	C2	C4	H12	109.730
C3	C1	O5	125.843	C4	C2	O6	125.843
H7	C3	H9	110.383	H7	C3	H10	110.383
H8	C4	H11	110.383	H8	C4	H12	110.383
H9	C3	H10	106.470	H11	C4	H12	106.470

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at BLYP/3-21G Charges (e)

Number	Element	Mulliken
1	C	0.335
2	C	0.335
3	C	-0.583
4	C	-0.583
5	O	-0.396
6	O	-0.396
7	H	0.205
8	H	0.205
9	H	0.219
10	H	0.219
11	H	0.219
12	H	0.219

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	-37.922	6.556	0.000
y	6.556	-36.617	0.000
z	0.000	0.000	-33.640

Traceless
	x	y	z
x	-2.794	6.556	0.000
y	6.556	-0.836	0.000
z	0.000	0.000	3.629

Polar
3z²-r²	7.259
x²-y²	-1.305
xy	6.556
xz	0.000
yz	0.000

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

	x	y	z
x	7.712	0.107	0.000
y	0.107	6.929	0.000
z	0.000	0.000	4.217

<r²> (average value of r²) Å²

<r²>	165.494
(<r²>)^1/2	12.864

Conformer 3 (CI)

Jump to S1C1 S1C2

Energy calculated at BLYP/3-21G

	hartrees
Energy at 0K	-304.687372
Energy at 298.15K	-304.693214
Nuclear repulsion energy	222.690138

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/3-21G

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3104	3087	0.00
2	A_g	3044	3027	0.00
3	A_g	2975	2958	0.00
4	A_g	1643	1634	0.00
5	A_g	1505	1497	0.00
6	A_g	1488	1479	0.00
7	A_g	1392	1384	0.00
8	A_g	1175	1168	0.00
9	A_g	1077	1071	0.00
10	A_g	989	984	0.00
11	A_g	656	653	0.00
12	A_g	617	613	0.00
13	A_g	524	521	0.00
14	A_g	378	376	0.00
15	A_g	33	33	0.00
16	A_u	3104	3087	3.78
17	A_u	3044	3027	13.62
18	A_u	2975	2958	3.68
19	A_u	1654	1645	85.30
20	A_u	1503	1495	32.44
21	A_u	1484	1476	30.40
22	A_u	1391	1383	108.49
23	A_u	1110	1104	118.50
24	A_u	980	975	10.50
25	A_u	888	883	33.28
26	A_u	511	508	17.00
27	A_u	380	378	2.87
28	A_u	278	277	19.38
29	A_u	108	107	6.47
30	A_u	15	15	2.79

Unscaled Zero Point Vibrational Energy (zpe) 20011.6 cm^-1
Scaled (by 0.9945) Zero Point Vibrational Energy (zpe) 19901.5 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 BLYP/3-21G

A	B	C
0.16628	0.11212	0.06869

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

Geometric Data calculated at BLYP/3-21G

Point Group is C_i

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	-0.783
C2	0.000	0.000	0.783
C3	1.391	0.000	-1.407
C4	-1.391	0.000	1.407
O5	-1.079	0.000	-1.407
O6	1.079	0.000	1.407
H7	1.649	1.035	-1.702
H8	-1.649	-1.035	1.702
H9	2.131	-0.340	-0.672
H10	1.400	-0.617	-2.318
H11	-2.131	0.340	0.672
H12	-1.400	0.617	2.318

Atom - Atom Distances (Å)

	C1	C2	C3	C4	O5	O6	H7	H8	H9	H10	H11	H12
C1		1.5652	1.5245	2.5941	1.2470	2.4414	2.1529	3.1562	2.1606	2.1670	2.6025	3.4571
C2	1.5652		2.5941	1.5245	2.4414	1.2470	3.1562	2.1529	2.6025	3.4571	2.1606	2.1670
C3	1.5245	2.5941		3.9569	2.4699	2.8317	1.1066	4.4694	1.0970	1.0999	4.1038	4.6948
C4	2.5941	1.5245	3.9569		2.8317	2.4699	4.4694	1.1066	4.1038	4.6948	1.0970	1.0999
O5	1.2470	2.4414	2.4699	2.8317		3.5470	2.9327	3.3258	3.3106	2.7118	2.3551	3.7894
O6	2.4414	1.2470	2.8317	2.4699	3.5470		3.3258	2.9327	2.3551	3.7894	3.3106	2.7118
H7	2.1529	3.1562	1.1066	4.4694	2.9327	3.3258		5.1714	1.7837	1.7807	4.5173	5.0619
H8	3.1562	2.1529	4.4694	1.1066	3.3258	2.9327	5.1714		4.5173	5.0619	1.7837	1.7807
H9	2.1606	2.6025	1.0970	4.1038	3.3106	2.3551	1.7837	4.5173		1.8217	4.5202	4.7244
H10	2.1670	3.4571	1.0999	4.6948	2.7118	3.7894	1.7807	5.0619	1.8217		4.7244	5.5539
H11	2.6025	2.1606	4.1038	1.0970	2.3551	3.3106	4.5173	1.7837	4.5202	4.7244		1.8217
H12	3.4571	2.1670	4.6948	1.0999	3.7894	2.7118	5.0619	1.7807	4.7244	5.5539	1.8217

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	114.188	C1	C2	O6	120.064
C1	C3	H7	108.782	C1	C3	H9	109.940
C1	C3	H10	110.277	C2	C1	C3	114.188
C2	C1	O5	120.064	C2	C4	H8	108.782
C2	C4	H11	109.940	C2	C4	H12	110.277
C3	C1	O5	125.748	C4	C2	O6	125.748
H7	C3	H9	108.086	H7	C3	H10	107.615
H8	C4	H11	108.086	H8	C4	H12	107.615
H9	C3	H10	112.036	H11	C4	H12	112.036

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at BLYP/3-21G Charges (e)

Number	Element	Mulliken
1	C	0.344
2	C	0.344
3	C	-0.596
4	C	-0.596
5	O	-0.399
6	O	-0.399
7	H	0.221
8	H	0.221
9	H	0.216
10	H	0.213
11	H	0.216
12	H	0.213

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	-36.955	0.327	-6.749
y	0.327	-33.653	-0.262
z	-6.749	-0.262	-37.315

Traceless
	x	y	z
x	-1.471	0.327	-6.749
y	0.327	3.482	-0.262
z	-6.749	-0.262	-2.011

Polar
3z²-r²	-4.021
x²-y²	-3.302
xy	0.327
xz	-6.749
yz	-0.262

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

	x	y	z
x	7.643	0.130	-0.356
y	0.130	4.266	0.026
z	-0.356	0.026	7.155

<r²> (average value of r²) Å²

<r²>	166.125
(<r²>)^1/2	12.889

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

using model chemistry: BLYP/3-21G

States and conformations

Conformer 1 (C2H)

Conformer 2 (C2)

Conformer 3 (CI)

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

using model chemistry: BLYP/3-21G

States and conformations

Conformer 1 (C2H)

Conformer 2 (C2)

Conformer 3 (CI)

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