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	hartrees
Energy at 0K	-154.212728
Energy at 298.15K	-154.215785
HF Energy	-153.653497
Nuclear repulsion energy	97.880107

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3287	3144	0.00
2	A_g	1609	1540	0.00
3	A_g	1131	1082	0.00
4	A_g	960	918	0.00
5	A_u	829	793	0.00
6	A_u	522	499	0.00
7	B_1g	849	813	0.00
8	B_1u	3274	3132	17.41
9	B_1u	1632	1562	2.61
10	B_1u	1052	1007	0.08
11	B_2g	587	562	0.00
12	B_2u	3253	3112	8.72
13	B_2u	1281	1226	29.83
14	B_2u	744	712	7.85
15	B_3g	3241	3101	0.00
16	B_3g	1193	1142	0.00
17	B_3g	882	844	0.00
18	B_3u	595	569	111.13

Atom	y (Å)	z (Å)
C1	0.676	0.791
C2	0.676	-0.791
C3	-0.676	0.791
C4	-0.676	-0.791
H5	1.451	1.562
H6	1.451	-1.562
H7	-1.451	1.562
H8	-1.451	-1.562

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5814	1.3527	2.0811	1.0932	2.4771	2.2628	3.1719
C2	1.5814		2.0811	1.3527	2.4771	1.0932	3.1719	2.2628
C3	1.3527	2.0811		1.5814	2.2628	3.1719	1.0932	2.4771
C4	2.0811	1.3527	1.5814		3.1719	2.2628	2.4771	1.0932
H5	1.0932	2.4771	2.2628	3.1719		3.1244	2.9016	4.2640
H6	2.4771	1.0932	3.1719	2.2628	3.1244		4.2640	2.9016
H7	2.2628	3.1719	1.0932	2.4771	2.9016	4.2640		3.1244
H8	3.1719	2.2628	2.4771	1.0932	4.2640	2.9016	3.1244

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	134.891
C1	C3	C4	90.000	C1	C3	H7	135.109
C2	C1	C3	90.000	C2	C1	H5	134.891
C2	C4	C3	90.000	C3	C1	H5	135.109
C4	C2	H6	135.109	C4	C3	H7	134.891

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: CCD/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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All results from a given calculation for C4H4 (cyclobutadiene)

using model chemistry: CCD/cc-pVDZ

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)