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	hartrees
Energy at 0K	-153.027617
Energy at 298.15K	-153.026726
HF Energy	-152.496446
Nuclear repulsion energy	76.552894

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3540	3308	0.00
2	Σ_g	2229	2083	0.00
3	Σ_g	909	849	0.00
4	Σ_u	3540	3307	160.18
5	Σ_u	2038	1904	0.18
6	Π_g	626	585	0.00
6	Π_g	626	585	0.00
7	Π_g	521	486	0.00
7	Π_g	521	486	0.00
8	Π_u	549	513	94.42
8	Π_u	549	513	94.42
9	Π_u	256	239	2.55
9	Π_u	256	239	2.55

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.687
C2	0.000	0.000	-0.687
C3	0.000	0.000	1.910
C4	0.000	0.000	-1.910
H5	0.000	0.000	2.972
H6	0.000	0.000	-2.972

	C1	C2	C3	C4	H5	H6
C1		1.3732	1.2235	2.5967	2.2858	3.6590
C2	1.3732		2.5967	1.2235	3.6590	2.2858
C3	1.2235	2.5967		3.8203	1.0623	4.8826
C4	2.5967	1.2235	3.8203		4.8826	1.0623
H5	2.2858	3.6590	1.0623	4.8826		5.9448
H6	3.6590	2.2858	4.8826	1.0623	5.9448

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**

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**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)