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	hartrees
Energy at 0K	-153.323011
Energy at 298.15K	-153.322211
HF Energy	-153.146278
Nuclear repulsion energy	76.848069

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3512	3331	0.00
2	Σ_g	2265	2148	0.00
3	Σ_g	919	871	0.00
4	Σ_u	3513	3332	159.72
5	Σ_u	2089	1981	0.03
6	Π_g	641	608	0.00
6	Π_g	641	608	0.00
7	Π_g	571	541	0.00
7	Π_g	571	541	0.00
8	Π_u	552	523	96.86
8	Π_u	552	523	96.86
9	Π_u	262	248	3.36
9	Π_u	262	248	3.36

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	1.903
C4	0.000	0.000	-1.903
H5	0.000	0.000	2.969
H6	0.000	0.000	-2.969

	C1	C2	C3	C4	H5	H6
C1		1.3761	1.2150	2.5911	2.2807	3.6568
C2	1.3761		2.5911	1.2150	3.6568	2.2807
C3	1.2150	2.5911		3.8062	1.0657	4.8718
C4	2.5911	1.2150	3.8062		4.8718	1.0657
H5	2.2807	3.6568	1.0657	4.8718		5.9375
H6	3.6568	2.2807	4.8718	1.0657	5.9375

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/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: B2PLYP=FULL/6-31G*

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)