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	hartrees
Energy at 0K	-153.018666
Energy at 298.15K	-153.017574
HF Energy	-152.495961
Nuclear repulsion energy	76.912958

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3534	3316	0.00
2	Σ_g	2368	2222	0.00
3	Σ_g	917	861	0.00
4	Σ_u	3535	3317	145.72
5	Σ_u	2179	2044	0.01
6	Π_g	630	592	0.00
6	Π_g	630	592	0.00
7	Π_g	416	390	0.00
7	Π_g	416	390	0.00
8	Π_u	537	503	105.40
8	Π_u	537	503	105.40
9	Π_u	255	239	1.97
9	Π_u	255	239	1.97

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	2.968
H6	0.000	0.000	-2.968

	C1	C2	C3	C4	H5	H6
C1		1.3839	1.2096	2.5935	2.2763	3.6602
C2	1.3839		2.5935	1.2096	3.6602	2.2763
C3	1.2096	2.5935		3.8030	1.0667	4.8698
C4	2.5935	1.2096	3.8030		4.8698	1.0667
H5	2.2763	3.6602	1.0667	4.8698		5.9365
H6	3.6602	2.2763	4.8698	1.0667	5.9365

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/6-31G*

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: MP3=FULL/6-31G*

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)