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	hartrees
Energy at 0K	-154.400764
Energy at 298.15K	-154.403698
HF Energy	-153.695955
Nuclear repulsion energy	98.429931

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)
1	A_g	3250	3142
2	A_g	1535	1484
3	A_g	1112	1075
4	A_g	944	913
5	A_u	762	737
6	A_u	472	456
7	B_1g	824	796
8	B_1u	3237	3130
9	B_1u	1561	1509
10	B_1u	1041	1007
11	B_2g	552	534
12	B_2u	3218	3111
13	B_2u	1256	1214
14	B_2u	717	693
15	B_3g	3203	3097
16	B_3g	1165	1126
17	B_3g	856	827
18	B_3u	585	565

Atom	y (Å)	z (Å)
C1	0.674	0.786
C2	0.674	-0.786
C3	-0.674	0.786
C4	-0.674	-0.786
H5	1.439	1.550
H6	1.439	-1.550
H7	-1.439	1.550
H8	-1.439	-1.550

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5728	1.3485	2.0718	1.0807	2.4584	2.2470	3.1503
C2	1.5728		2.0718	1.3485	2.4584	1.0807	3.1503	2.2470
C3	1.3485	2.0718		1.5728	2.2470	3.1503	1.0807	2.4584
C4	2.0718	1.3485	1.5728		3.1503	2.2470	2.4584	1.0807
H5	1.0807	2.4584	2.2470	3.1503		3.1000	2.8779	4.2300
H6	2.4584	1.0807	3.1503	2.2470	3.1000		4.2300	2.8779
H7	2.2470	3.1503	1.0807	2.4584	2.8779	4.2300		3.1000
H8	3.1503	2.2470	2.4584	1.0807	4.2300	2.8779	3.1000

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	134.960
C1	C3	C4	90.000	C1	C3	H7	135.040
C2	C1	C3	90.000	C2	C1	H5	134.960
C2	C4	C3	90.000	C3	C1	H5	135.040
C4	C2	H6	135.040	C4	C3	H7	134.960

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: QCISD(T)/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: QCISD(T)/aug-cc-pVTZ

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)