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	hartrees
Energy at 0K	-153.431164
Energy at 298.15K	-153.430620
HF Energy	-153.431164
Nuclear repulsion energy	77.110826

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3519	3337	0.00
2	Σ_g	2330	2209	0.00
3	Σ_g	933	885	0.00
4	Σ_u	3521	3339	167.36
5	Σ_u	2148	2037	0.65
6	Π_g	723	686	0.00
6	Π_g	723	686	0.00
7	Π_g	625	593	0.00
7	Π_g	625	593	0.00
8	Π_u	626	594	101.32
8	Π_u	626	594	101.32
9	Π_u	269	255	5.98
9	Π_u	269	255	5.98

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.684
C2	0.000	0.000	-0.684
C3	0.000	0.000	1.894
C4	0.000	0.000	-1.894
H5	0.000	0.000	2.960
H6	0.000	0.000	-2.960

	C1	C2	C3	C4	H5	H6
C1		1.3676	1.2102	2.5778	2.2761	3.6437
C2	1.3676		2.5778	1.2102	3.6437	2.2761
C3	1.2102	2.5778		3.7880	1.0659	4.8539
C4	2.5778	1.2102	3.7880		4.8539	1.0659
H5	2.2761	3.6437	1.0659	4.8539		5.9198
H6	3.6437	2.2761	4.8539	1.0659	5.9198

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: mPW1PW91/6-31G*

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	0.641
2	C	0.641
3	C	-0.912
4	C	-0.912
5	H	0.271
6	H	0.271

<r²>	78.337
(<r²>)^1/2	8.851

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: mPW1PW91/6-31G*

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)