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	hartrees
Energy at 0K	-152.004340
Energy at 298.15K	-152.007353
HF Energy	-151.739221
Nuclear repulsion energy	97.219864

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3568	3172	0.00
2	A_g	1642	1460	0.00
3	A_g	1250	1111	0.00
4	A_g	1054	937	0.00
5	A_u	908	807	0.00
6	A_u	565	502	0.00
7	B_1g	926	824	0.00
8	B_1u	3552	3157	0.07
9	B_1u	1663	1478	1.54
10	B_1u	1129	1003	5.53
11	B_2g	667	593	0.00
12	B_2u	3526	3134	8.39
13	B_2u	1410	1253	15.20
14	B_2u	848	753	0.07
15	B_3g	3519	3128	0.00
16	B_3g	1289	1146	0.00
17	B_3g	952	847	0.00
18	B_3u	642	571	44.47

Atom	y (Å)	z (Å)
C1	0.681	0.796
C2	0.681	-0.796
C3	-0.681	0.796
C4	-0.681	-0.796
H5	1.468	1.563
H6	1.468	-1.563
H7	-1.468	1.563
H8	-1.468	-1.563

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5926	1.3624	2.0958	1.0990	2.4875	2.2822	3.1919
C2	1.5926		2.0958	1.3624	2.4875	1.0990	3.1919	2.2822
C3	1.3624	2.0958		1.5926	2.2822	3.1919	1.0990	2.4875
C4	2.0958	1.3624	1.5926		3.1919	2.2822	2.4875	1.0990
H5	1.0990	2.4875	2.2822	3.1919		3.1269	2.9363	4.2895
H6	2.4875	1.0990	3.1919	2.2822	3.1269		4.2895	2.9363
H7	2.2822	3.1919	1.0990	2.4875	2.9363	4.2895		3.1269
H8	3.1919	2.2822	2.4875	1.0990	4.2895	2.9363	3.1269

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	134.271
C1	C3	C4	90.000	C1	C3	H7	135.729
C2	C1	C3	90.000	C2	C1	H5	134.271
C2	C4	C3	90.000	C3	C1	H5	135.729
C4	C2	H6	135.729	C4	C3	H7	134.271

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: MP2=FULL/STO-3G

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=FULL/STO-3G

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)