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	hartrees
Energy at 0K	-153.492550
Energy at 298.15K	-153.491645
HF Energy	-153.492550
Nuclear repulsion energy	76.902515

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3405	3396	0.00
2	Σ_g	2202	2197	0.00
3	Σ_g	904	901	0.00
4	Σ_u	3407	3399	189.44
5	Σ_u	2041	2036	5.65
6	Π_g	602	600	0.00
6	Π_g	602	600	0.00
7	Π_g	510	509	0.00
7	Π_g	510	509	0.00
8	Π_u	609	608	98.79
8	Π_u	609	608	98.79
9	Π_u	232	231	7.43
9	Π_u	232	231	7.43

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.681
C2	0.000	0.000	-0.681
C3	0.000	0.000	1.899
C4	0.000	0.000	-1.899
H5	0.000	0.000	2.967
H6	0.000	0.000	-2.967

	C1	C2	C3	C4	H5	H6
C1		1.3626	1.2180	2.5806	2.2856	3.6482
C2	1.3626		2.5806	1.2180	3.6482	2.2856
C3	1.2180	2.5806		3.7986	1.0676	4.8662
C4	2.5806	1.2180	3.7986		4.8662	1.0676
H5	2.2856	3.6482	1.0676	4.8662		5.9339
H6	3.6482	2.2856	4.8662	1.0676	5.9339

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: BLYP/TZVP

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	-0.082
2	C	-0.082
3	C	-0.097
4	C	-0.097
5	H	0.179
6	H	0.179

<r²>	79.421
(<r²>)^1/2	8.912

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: BLYP/TZVP

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)