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	hartrees
Energy at 0K	-153.448430
Energy at 298.15K	-153.447545
HF Energy	-153.448430
Nuclear repulsion energy	77.287540

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3474	3344	0.00
2	Σ_g	2296	2211	0.00
3	Σ_g	922	888	0.00
4	Σ_u	3476	3346	149.69
5	Σ_u	2113	2034	1.36
6	Π_g	620	597	0.00
6	Π_g	620	597	0.00
7	Π_g	514	495	0.00
7	Π_g	514	495	0.00
8	Π_u	609	586	90.16
8	Π_u	609	586	90.16
9	Π_u	233	225	6.23
9	Π_u	233	225	6.23

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.682
C2	0.000	0.000	-0.682
C3	0.000	0.000	1.889
C4	0.000	0.000	-1.889
H5	0.000	0.000	2.954
H6	0.000	0.000	-2.954

	C1	C2	C3	C4	H5	H6
C1		1.3635	1.2076	2.5711	2.2725	3.6360
C2	1.3635		2.5711	1.2076	3.6360	2.2725
C3	1.2076	2.5711		3.7787	1.0649	4.8436
C4	2.5711	1.2076	3.7787		4.8436	1.0649
H5	2.2725	3.6360	1.0649	4.8436		5.9085
H6	3.6360	2.2725	4.8436	1.0649	5.9085

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: B3PW91/6-311G*

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	-0.124
2	C	-0.124
3	C	-0.152
4	C	-0.152
5	H	0.276
6	H	0.276

<r²>	78.372
(<r²>)^1/2	8.853

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: B3PW91/6-311G*

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)