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	hartrees
Energy at 0K	-154.381146
Energy at 298.15K	-154.376491
HF Energy	-153.639422
Nuclear repulsion energy	99.524548

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3433	3433	0.00
2	A_g	1782	1782	0.00
3	A_g	1210	1210	0.00
4	A_g	1030	1030	0.00
5	A_u	995	995	0.00
6	A_u	606	606	0.00
7	B_1g	980	980	0.00
8	B_1u	3422	3422	26.02
9	B_1u	1803	1803	5.31
10	B_1u	1153	1153	0.00
11	B_2g	696	696	0.00
12	B_2u	3398	3398	14.22
13	B_2u	1393	1393	36.83
14	B_2u	806	806	12.93
15	B_3g	3381	3381	0.00
16	B_3g	1287	1287	0.00
17	B_3g	921	921	0.00
18	B_3u	674	674	142.15

Atom	y (Å)	z (Å)
C1	0.660	0.784
C2	0.660	-0.784
C3	-0.660	0.784
C4	-0.660	-0.784
H5	1.425	1.540
H6	1.425	-1.540
H7	-1.425	1.540
H8	-1.425	-1.540

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5683	1.3206	2.0502	1.0752	2.4465	2.2182	3.1225
C2	1.5683		2.0502	1.3206	2.4465	1.0752	3.1225	2.2182
C3	1.3206	2.0502		1.5683	2.2182	3.1225	1.0752	2.4465
C4	2.0502	1.3206	1.5683		3.1225	2.2182	2.4465	1.0752
H5	1.0752	2.4465	2.2182	3.1225		3.0794	2.8505	4.1962
H6	2.4465	1.0752	3.1225	2.2182	3.0794		4.1962	2.8505
H7	2.2182	3.1225	1.0752	2.4465	2.8505	4.1962		3.0794
H8	3.1225	2.2182	2.4465	1.0752	4.1962	2.8505	3.0794

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	134.646
C1	C3	C4	90.000	C1	C3	H7	135.354
C2	C1	C3	90.000	C2	C1	H5	134.646
C2	C4	C3	90.000	C3	C1	H5	135.354
C4	C2	H6	135.354	C4	C3	H7	134.646

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: CBS-Q

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: CBS-Q

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)