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	hartrees
Energy at 0K	-154.338799
Energy at 298.15K	-154.341767
HF Energy	-153.696883
Nuclear repulsion energy	98.745416

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3281	3126	0.00
2	A_g	1566	1493	0.00
3	A_g	1121	1068	0.00
4	A_g	967	921	0.00
5	A_u	791	754	0.00
6	A_u	476	453	0.00
7	B_1g	857	817	0.00
8	B_1u	3270	3116	11.73
9	B_1u	1574	1500	5.49
10	B_1u	1052	1002	0.10
11	B_2g	566	539	0.00
12	B_2u	3248	3095	5.86
13	B_2u	1256	1197	33.72
14	B_2u	722	688	8.26
15	B_3g	3234	3082	0.00
16	B_3g	1178	1122	0.00
17	B_3g	846	807	0.00
18	B_3u	574	547	133.95

Atom	y (Å)	z (Å)
C1	0.672	0.784
C2	0.672	-0.784
C3	-0.672	0.784
C4	-0.672	-0.784
H5	1.434	1.548
H6	1.434	-1.548
H7	-1.434	1.548
H8	-1.434	-1.548

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5678	1.3432	2.0645	1.0790	2.4530	2.2396	3.1415
C2	1.5678		2.0645	1.3432	2.4530	1.0790	3.1415	2.2396
C3	1.3432	2.0645		1.5678	2.2396	3.1415	1.0790	2.4530
C4	2.0645	1.3432	1.5678		3.1415	2.2396	2.4530	1.0790
H5	1.0790	2.4530	2.2396	3.1415		3.0955	2.8673	4.2194
H6	2.4530	1.0790	3.1415	2.2396	3.0955		4.2194	2.8673
H7	2.2396	3.1415	1.0790	2.4530	2.8673	4.2194		3.0955
H8	3.1415	2.2396	2.4530	1.0790	4.2194	2.8673	3.0955

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	135.069
C1	C3	C4	90.000	C1	C3	H7	134.931
C2	C1	C3	90.000	C2	C1	H5	135.069
C2	C4	C3	90.000	C3	C1	H5	134.931
C4	C2	H6	134.931	C4	C3	H7	135.069

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: MP2/aug-cc-pVTZ

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: MP2/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)