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	hartrees
Energy at 0K	-153.043804
Energy at 298.15K	-153.043117
HF Energy	-152.507493
Nuclear repulsion energy	76.861215

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3555	3312	0.00
2	Σ_g	2353	2192	0.00
3	Σ_g	914	851	0.00
4	Σ_u	3555	3312	157.07
5	Σ_u	2164	2016	1.82
6	Π_g	633	590	0.00
6	Π_g	633	590	0.00
7	Π_g	578	538	0.00
7	Π_g	578	538	0.00
8	Π_u	635	592	122.78
8	Π_u	635	592	122.78
9	Π_u	259	241	8.04
9	Π_u	259	241	8.04

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.692
C2	0.000	0.000	-0.692
C3	0.000	0.000	1.902
C4	0.000	0.000	-1.902
H5	0.000	0.000	2.964
H6	0.000	0.000	-2.964

	C1	C2	C3	C4	H5	H6
C1		1.3840	1.2099	2.5939	2.2715	3.6555
C2	1.3840		2.5939	1.2099	3.6555	2.2715
C3	1.2099	2.5939		3.8038	1.0616	4.8654
C4	2.5939	1.2099	3.8038		4.8654	1.0616
H5	2.2715	3.6555	1.0616	4.8654		5.9270
H6	3.6555	2.2715	4.8654	1.0616	5.9270

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: MP3=FULL/6-31+G**

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: MP3=FULL/6-31+G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)