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	hartrees
Energy at 0K	-153.123200
Energy at 298.15K	-153.122142
HF Energy	-152.512164
Nuclear repulsion energy	77.064833

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3543	3330	0.00
2	Σ_g	2241	2106	0.00
3	Σ_g	912	858	0.00
4	Σ_u	3541	3329	186.62
5	Σ_u	2042	1919	0.51
6	Π_g	588	553	0.00
6	Π_g	588	553	0.00
7	Π_g	494	464	0.00
7	Π_g	494	464	0.00
8	Π_u	554	521	75.98
8	Π_u	554	521	75.98
9	Π_u	220	206	3.21
9	Π_u	220	206	3.21

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.681
C2	0.000	0.000	-0.681
C3	0.000	0.000	1.896
C4	0.000	0.000	-1.896
H5	0.000	0.000	2.957
H6	0.000	0.000	-2.957

	C1	C2	C3	C4	H5	H6
C1		1.3615	1.2156	2.5771	2.2760	3.6375
C2	1.3615		2.5771	1.2156	3.6375	2.2760
C3	1.2156	2.5771		3.7927	1.0604	4.8531
C4	2.5771	1.2156	3.7927		4.8531	1.0604
H5	2.2760	3.6375	1.0604	4.8531		5.9135
H6	3.6375	2.2760	4.8531	1.0604	5.9135

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

All results from a given calculation for C₄H₂ (Diacetylene)

using model chemistry: MP2=FULL/6-31G(2df,p)

States and conformations

	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 C4H2 (Diacetylene)

using model chemistry: MP2=FULL/6-31G(2df,p)

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)