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	hartrees
Energy at 0K	-154.358524
Energy at 298.15K	-154.361593
HF Energy	-153.697666
Nuclear repulsion energy	98.912955

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3283	3142	0.00
2	A_g	1617	1547	0.00
3	A_g	1135	1086	0.00
4	A_g	969	928	0.00
5	A_u	820	785	0.00
6	A_u	500	479	0.00
7	B_1g	879	841	0.00
8	B_1u	3271	3130	12.36
9	B_1u	1634	1563	6.22
10	B_1u	1065	1019	0.01
11	B_2g	595	569	0.00
12	B_2u	3250	3110	7.56
13	B_2u	1283	1227	33.12
14	B_2u	744	712	9.58
15	B_3g	3236	3097	0.00
16	B_3g	1195	1144	0.00
17	B_3g	879	841	0.00
18	B_3u	606	580	131.95

Atom	y (Å)	z (Å)
C1	0.668	0.785
C2	0.668	-0.785
C3	-0.668	0.785
C4	-0.668	-0.785
H5	1.431	1.547
H6	1.431	-1.547
H7	-1.431	1.547
H8	-1.431	-1.547

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5698	1.3365	2.0617	1.0782	2.4532	2.2335	3.1375
C2	1.5698		2.0617	1.3365	2.4532	1.0782	3.1375	2.2335
C3	1.3365	2.0617		1.5698	2.2335	3.1375	1.0782	2.4532
C4	2.0617	1.3365	1.5698		3.1375	2.2335	2.4532	1.0782
H5	1.0782	2.4532	2.2335	3.1375		3.0933	2.8625	4.2146
H6	2.4532	1.0782	3.1375	2.2335	3.0933		4.2146	2.8625
H7	2.2335	3.1375	1.0782	2.4532	2.8625	4.2146		3.0933
H8	3.1375	2.2335	2.4532	1.0782	4.2146	2.8625	3.0933

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	134.954
C1	C3	C4	90.000	C1	C3	H7	135.046
C2	C1	C3	90.000	C2	C1	H5	134.954
C2	C4	C3	90.000	C3	C1	H5	135.046
C4	C2	H6	135.046	C4	C3	H7	134.954

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: CCD/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: CCD/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)