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	hartrees
Energy at 0K	-153.333924
Energy at 298.15K	-153.333165
HF Energy	-153.158342
Nuclear repulsion energy	76.406367

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3493	3348	0.00
2	Σ_g	2244	2151	0.00
3	Σ_g	913	875	0.00
4	Σ_u	3494	3349	190.16
5	Σ_u	2068	1982	0.27
6	Π_g	641	614	0.00
6	Π_g	641	614	0.00
7	Π_g	552	529	0.00
7	Π_g	552	529	0.00
8	Π_u	631	605	80.53
8	Π_u	631	605	80.53
9	Π_u	239	229	5.29
9	Π_u	239	229	5.29

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.688
C2	0.000	0.000	-0.688
C3	0.000	0.000	1.912
C4	0.000	0.000	-1.912
H5	0.000	0.000	2.984
H6	0.000	0.000	-2.984

	C1	C2	C3	C4	H5	H6
C1		1.3760	1.2241	2.6001	2.2964	3.6724
C2	1.3760		2.6001	1.2241	3.6724	2.2964
C3	1.2241	2.6001		3.8243	1.0723	4.8965
C4	2.6001	1.2241	3.8243		4.8965	1.0723
H5	2.2964	3.6724	1.0723	4.8965		5.9688
H6	3.6724	2.2964	4.8965	1.0723	5.9688

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: B2PLYP=FULL/cc-pVDZ

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: B2PLYP=FULL/cc-pVDZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)