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	hartrees
Energy at 0K	-154.248467
Energy at 298.15K	-154.251413
HF Energy	-153.651932
Nuclear repulsion energy	97.529459

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)
1	A_g	3268	3154
2	A_g	1551	1496
3	A_g	1111	1073
4	A_g	945	912
5	A_u	787	759
6	A_u	504	486
7	B_1g	810	782
8	B_1u	3256	3142
9	B_1u	1568	1513
10	B_1u	1035	998
11	B_2g	555	535
12	B_2u	3235	3122
13	B_2u	1257	1213
14	B_2u	714	689
15	B_3g	3222	3109
16	B_3g	1165	1124
17	B_3g	856	826
18	B_3u	569	549

Atom	y (Å)	z (Å)
C1	0.681	0.792
C2	0.681	-0.792
C3	-0.681	0.792
C4	-0.681	-0.792
H5	1.455	1.565
H6	1.455	-1.565
H7	-1.455	1.565
H8	-1.455	-1.565

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5847	1.3612	2.0890	1.0942	2.4814	2.2715	3.1811
C2	1.5847		2.0890	1.3612	2.4814	1.0942	3.1811	2.2715
C3	1.3612	2.0890		1.5847	2.2715	3.1811	1.0942	2.4814
C4	2.0890	1.3612	1.5847		3.1811	2.2715	2.4814	1.0942
H5	1.0942	2.4814	2.2715	3.1811		3.1299	2.9109	4.2743
H6	2.4814	1.0942	3.1811	2.2715	3.1299		4.2743	2.9109
H7	2.2715	3.1811	1.0942	2.4814	2.9109	4.2743		3.1299
H8	3.1811	2.2715	2.4814	1.0942	4.2743	2.9109	3.1299

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	134.917
C1	C3	C4	90.000	C1	C3	H7	135.083
C2	C1	C3	90.000	C2	C1	H5	134.917
C2	C4	C3	90.000	C3	C1	H5	135.083
C4	C2	H6	135.083	C4	C3	H7	134.917

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: MP4=FULL/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: MP4=FULL/cc-pVDZ

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)