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	hartrees
Energy at 0K	-153.473412
Energy at 298.15K	-153.472725
HF Energy	-153.473412
Nuclear repulsion energy	77.379202

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3499	3347	0.00
2	Σ_g	2313	2213	0.00
3	Σ_g	926	886	0.00
4	Σ_u	3500	3349	185.37
5	Σ_u	2130	2037	1.31
6	Π_g	684	655	0.00
6	Π_g	684	655	0.00
7	Π_g	536	513	0.00
7	Π_g	536	513	0.00
8	Π_u	684	654	82.40
8	Π_u	684	654	82.40
9	Π_u	236	226	8.09
9	Π_u	236	226	8.09

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	1.887
C4	0.000	0.000	-1.887
H5	0.000	0.000	2.950
H6	0.000	0.000	-2.950

	C1	C2	C3	C4	H5	H6
C1		1.3644	1.2052	2.5695	2.2678	3.6322
C2	1.3644		2.5695	1.2052	3.6322	2.2678
C3	1.2052	2.5695		3.7747	1.0627	4.8373
C4	2.5695	1.2052	3.7747		4.8373	1.0627
H5	2.2678	3.6322	1.0627	4.8373		5.9000
H6	3.6322	2.2678	4.8373	1.0627	5.9000

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: mPW1PW91/6-311G**

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	-0.061
2	C	-0.061
3	C	-0.054
4	C	-0.054
5	H	0.115
6	H	0.115

<r²>	78.245
(<r²>)^1/2	8.846

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: mPW1PW91/6-311G**

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)