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	hartrees
Energy at 0K	-153.450427
Energy at 298.15K	-153.448879
HF Energy	-153.450427
Nuclear repulsion energy	76.880176

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3502	3356	0.00
2	Σ_g	2315	2219	0.00
3	Σ_g	928	889	0.00
4	Σ_u	3503	3357	190.89
5	Σ_u	2127	2038	4.80
6	Π_g	620	595	0.00
6	Π_g	620	595	0.00
7	Π_g	213	205	0.00
7	Π_g	213	205	0.00
8	Π_u	619	593	89.01
8	Π_u	619	593	89.01
9	Π_u	214	205	7.36
9	Π_u	214	205	7.36

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	1.900
C4	0.000	0.000	-1.900
H5	0.000	0.000	2.969
H6	0.000	0.000	-2.969

	C1	C2	C3	C4	H5	H6
C1		1.3699	1.2147	2.5846	2.2838	3.6537
C2	1.3699		2.5846	1.2147	3.6537	2.2838
C3	1.2147	2.5846		3.7993	1.0691	4.8684
C4	2.5846	1.2147	3.7993		4.8684	1.0691
H5	2.2838	3.6537	1.0691	4.8684		5.9375
H6	3.6537	2.2838	4.8684	1.0691	5.9375

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/aug-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	0.415
2	C	0.415
3	C	0.320
4	C	0.320
5	H	-0.735
6	H	-0.735

<r²>	79.276
(<r²>)^1/2	8.904

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: mPW1PW91/aug-cc-pVDZ

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)