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	hartrees
Energy at 0K	-153.324411
Energy at 298.15K	-153.323724
HF Energy	-153.150274
Nuclear repulsion energy	76.821053

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3514	3514	0.00
2	Σ_g	2261	2261	0.00
3	Σ_g	918	918	0.00
4	Σ_u	3515	3515	171.97
5	Σ_u	2086	2086	0.06
6	Π_g	650	650	0.00
6	Π_g	650	650	0.00
7	Π_g	604	604	0.00
7	Π_g	604	604	0.00
8	Π_u	589	589	94.66
8	Π_u	589	589	94.66
9	Π_u	262	262	4.01
9	Π_u	262	262	4.01

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.685
C2	0.000	0.000	-0.685
C3	0.000	0.000	1.902
C4	0.000	0.000	-1.902
H5	0.000	0.000	2.966
H6	0.000	0.000	-2.966

	C1	C2	C3	C4	H5	H6
C1		1.3707	1.2171	2.5878	2.2806	3.6513
C2	1.3707		2.5878	1.2171	3.6513	2.2806
C3	1.2171	2.5878		3.8049	1.0635	4.8684
C4	2.5878	1.2171	3.8049		4.8684	1.0635
H5	2.2806	3.6513	1.0635	4.8684		5.9319
H6	3.6513	2.2806	4.8684	1.0635	5.9319

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/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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Number	Element	Mulliken
1	C	0.531
2	C	0.531
3	C	-0.753
4	C	-0.753
5	H	0.222
6	H	0.222

<r²>	78.987
(<r²>)^1/2	8.887

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: B2PLYP/6-31G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)