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	hartrees
Energy at 0K	-154.265847
Energy at 298.15K
HF Energy	-153.689787
Nuclear repulsion energy	98.881406

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3304	3132	0.00
2	A_g	1615	1531	0.00
3	A_g	1140	1081	0.00
4	A_g	973	922	0.00
5	A_u	617	585	0.00
6	A_u	383i	363i	0.00
7	B_1g	786	745	0.00
8	B_1u	3293	3121	17.96
9	B_1u	1637	1552	5.33
10	B_1u	1073	1018	0.25
11	B_2g	457	433	0.00
12	B_2u	3272	3102	10.37
13	B_2u	1296	1229	31.09
14	B_2u	748	710	7.59
15	B_3g	3259	3090	0.00
16	B_3g	1215	1152	0.00
17	B_3g	889	842	0.00
18	B_3u	578	548	142.65

Atom	y (Å)	z (Å)
C1	0.669	0.785
C2	0.669	-0.785
C3	-0.669	0.785
C4	-0.669	-0.785
H5	1.436	1.544
H6	1.436	-1.544
H7	-1.436	1.544
H8	-1.436	-1.544

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5698	1.3372	2.0621	1.0788	2.4515	2.2368	3.1383
C2	1.5698		2.0621	1.3372	2.4515	1.0788	3.1383	2.2368
C3	1.3372	2.0621		1.5698	2.2368	3.1383	1.0788	2.4515
C4	2.0621	1.3372	1.5698		3.1383	2.2368	2.4515	1.0788
H5	1.0788	2.4515	2.2368	3.1383		3.0871	2.8712	4.2159
H6	2.4515	1.0788	3.1383	2.2368	3.0871		4.2159	2.8712
H7	2.2368	3.1383	1.0788	2.4515	2.8712	4.2159		3.0871
H8	3.1383	2.2368	2.4515	1.0788	4.2159	2.8712	3.0871

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	134.687
C1	C3	C4	90.000	C1	C3	H7	135.313
C2	C1	C3	90.000	C2	C1	H5	134.687
C2	C4	C3	90.000	C3	C1	H5	135.313
C4	C2	H6	135.313	C4	C3	H7	134.687

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: CCD/TZVP

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: CCD/TZVP

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)