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State	Conformation	minimum conformation	conformer description	state description
1	1	no	D*H	¹Σ_g
1	2	yes	C2H	¹A_G

	hartrees
Energy at 0K	-153.118940
Energy at 298.15K
HF Energy	-152.523169
Nuclear repulsion energy	76.605443

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3488	3304	0.00
2	Σ_g	2205	2089	0.00
3	Σ_g	899	851	0.00
4	Σ_u	3488	3304	151.04
5	Σ_u	2006	1900	0.16
6	Π_g	581	550	0.00
6	Π_g	581	550	0.00
7	Π_g	205i	194i	0.00
7	Π_g	205i	194i	0.00
8	Π_u	484	459	91.43
8	Π_u	484	459	91.43
9	Π_u	210	199	1.03
9	Π_u	210	199	1.03

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.686
C2	0.000	0.000	-0.686
C3	0.000	0.000	1.908
C4	0.000	0.000	-1.908
H5	0.000	0.000	2.973
H6	0.000	0.000	-2.973

	C1	C2	C3	C4	H5	H6
C1		1.3711	1.2226	2.5936	2.2875	3.6586
C2	1.3711		2.5936	1.2226	3.6586	2.2875
C3	1.2226	2.5936		3.8162	1.0649	4.8812
C4	2.5936	1.2226	3.8162		4.8812	1.0649
H5	2.2875	3.6586	1.0649	4.8812		5.9461
H6	3.6586	2.2875	4.8812	1.0649	5.9461

All results from a given calculation for C₄H₂ (Diacetylene)

using model chemistry: MP2=FULL/6-311G*

States and conformations

Conformer 1 (D*H)

Conformer 2 (C2H)

	Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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You are here: Calculated > Energy > Optimized > Energy

	hartrees
Energy at 0K	-153.118942
Energy at 298.15K	-153.117346
HF Energy	-152.523064
Nuclear repulsion energy	76.592311

Atom	x (Å)	y (Å)
C1	-0.006	0.686
C2	0.006	-0.686
C3	0.006	1.908
C4	-0.006	-1.908
H5	-0.012	2.973
H6	0.012	-2.973

	C1	C2	C3	C4	H5	H6
C1		1.3714	1.2228	2.5941	2.2876	3.6590
C2	1.3714		2.5941	1.2228	3.6590	2.2876
C3	1.2228	2.5941		3.8169	1.0650	4.8817
C4	2.5941	1.2228	3.8169		4.8817	1.0650
H5	2.2876	3.6590	1.0650	4.8817		5.9465
H6	3.6590	2.2876	4.8817	1.0650	5.9465

atom1	atom2	atom3	angle		atom1	atom2	atom3	angle
C1	C2	C4	180.000		C1	C3	H5	180.000
C2	C1	C3	180.000		C2	C4	H6	180.000

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3488	3304	0.00
2	A_g	2204	2087	0.00
3	A_g	898	850	0.00
4	A_g	582	551	0.00
5	A_g	267	253	0.00
6	A_u	494	468	91.18
7	A_u	215	203	1.43
8	B_g	581	550	0.00
9	B_u	3488	3304	150.71
10	B_u	2005	1899	0.16
11	B_u	507	480	91.99
12	B_u	219	207	2.02

atom1	atom2	atom3	angle		atom1	atom2	atom3	angle
C1	C2	C4	178.931		C1	C3	H5	178.490
C2	C1	C3	178.931		C2	C4	H6	178.490

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: MP2=FULL/6-311G*

States and conformations

Conformer 1 (D*H)

Conformer 2 (C2H)

All results from a given calculation for C₄H₂ (Diacetylene)