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	hartrees
Energy at 0K	-154.474458
Energy at 298.15K	-154.477480
HF Energy	-153.697115
Nuclear repulsion energy	98.857071

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)
1	A_g	3264	3146
2	A_g	1555	1498
3	A_g	1118	1077
4	A_g	951	916
5	A_u	820	790
6	A_u	489	471
7	B_1g	854	823
8	B_1u	3245	3127
9	B_1u	1580	1522
10	B_1u	1050	1011
11	B_2g	595	573
12	B_2u	3219	3102
13	B_2u	1248	1203
14	B_2u	723	696
15	B_3g	3199	3083
16	B_3g	1170	1127
17	B_3g	852	821
18	B_3u	607	585

Atom	y (Å)	z (Å)
C1	0.671	0.783
C2	0.671	-0.783
C3	-0.671	0.783
C4	-0.671	-0.783
H5	1.433	1.543
H6	1.433	-1.543
H7	-1.433	1.543
H8	-1.433	-1.543

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5662	1.3426	2.0629	1.0759	2.4474	2.2374	3.1366
C2	1.5662		2.0629	1.3426	2.4474	1.0759	3.1366	2.2374
C3	1.3426	2.0629		1.5662	2.2374	3.1366	1.0759	2.4474
C4	2.0629	1.3426	1.5662		3.1366	2.2374	2.4474	1.0759
H5	1.0759	2.4474	2.2374	3.1366		3.0854	2.8664	4.2114
H6	2.4474	1.0759	3.1366	2.2374	3.0854		4.2114	2.8664
H7	2.2374	3.1366	1.0759	2.4474	2.8664	4.2114		3.0854
H8	3.1366	2.2374	2.4474	1.0759	4.2114	2.8664	3.0854

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	134.913
C1	C3	C4	90.000	C1	C3	H7	135.087
C2	C1	C3	90.000	C2	C1	H5	134.913
C2	C4	C3	90.000	C3	C1	H5	135.087
C4	C2	H6	135.087	C4	C3	H7	134.913

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: CCSD(T)=FULL/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: CCSD(T)=FULL/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)