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	hartrees
Energy at 0K	-153.296897
Energy at 298.15K	-153.296285
HF Energy	-153.296897
Nuclear repulsion energy	76.782460

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3502	3368	0.00
2	Σ_g	2321	2232	0.00
3	Σ_g	933	897	0.00
4	Σ_u	3503	3369	208.66
5	Σ_u	2135	2053	1.05
6	Π_g	686	659	0.00
6	Π_g	686	659	0.00
7	Π_g	581	559	0.00
7	Π_g	581	559	0.00
8	Π_u	674	648	84.07
8	Π_u	674	648	84.07
9	Π_u	245	236	6.81
9	Π_u	245	236	6.81

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	2.974
H6	0.000	0.000	-2.974

	C1	C2	C3	C4	H5	H6
C1		1.3708	1.2162	2.5870	2.2889	3.6598
C2	1.3708		2.5870	1.2162	3.6598	2.2889
C3	1.2162	2.5870		3.8032	1.0728	4.8759
C4	2.5870	1.2162	3.8032		4.8759	1.0728
H5	2.2889	3.6598	1.0728	4.8759		5.9487
H6	3.6598	2.2889	4.8759	1.0728	5.9487

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: PBE1PBE/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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Number	Element	Mulliken
1	C	0.625
2	C	0.625
3	C	-0.637
4	C	-0.637
5	H	0.012
6	H	0.012

<r²>	79.166
(<r²>)^1/2	8.898

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: PBE1PBE/cc-pVDZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)