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	hartrees
Energy at 0K	-152.729036
Energy at 298.15K	-152.732053
HF Energy	-152.729036
Nuclear repulsion energy	98.012443

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3532	3126	0.00
2	A_g	1767	1564	0.00
3	A_g	1237	1094	0.00
4	A_g	1042	922	0.00
5	A_u	923	817	0.00
6	A_u	567	502	0.00
7	B_1g	946	837	0.00
8	B_1u	3515	3110	1.44
9	B_1u	1784	1578	0.03
10	B_1u	1121	992	2.69
11	B_2g	679	601	0.00
12	B_2u	3479	3079	26.45
13	B_2u	1371	1214	35.04
14	B_2u	820	725	0.88
15	B_3g	3457	3059	0.00
16	B_3g	1253	1109	0.00
17	B_3g	930	823	0.00
18	B_3u	654	579	65.52

Atom	y (Å)	z (Å)
C1	0.670	0.794
C2	0.670	-0.794
C3	-0.670	0.794
C4	-0.670	-0.794
H5	1.458	1.557
H6	1.458	-1.557
H7	-1.458	1.557
H8	-1.458	-1.557

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5885	1.3407	2.0786	1.0964	2.4797	2.2608	3.1715
C2	1.5885		2.0786	1.3407	2.4797	1.0964	3.1715	2.2608
C3	1.3407	2.0786		1.5885	2.2608	3.1715	1.0964	2.4797
C4	2.0786	1.3407	1.5885		3.1715	2.2608	2.4797	1.0964
H5	1.0964	2.4797	2.2608	3.1715		3.1141	2.9159	4.2661
H6	2.4797	1.0964	3.1715	2.2608	3.1141		4.2661	2.9159
H7	2.2608	3.1715	1.0964	2.4797	2.9159	4.2661		3.1141
H8	3.1715	2.2608	2.4797	1.0964	4.2661	2.9159	3.1141

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	134.084
C1	C3	C4	90.000	C1	C3	H7	135.916
C2	C1	C3	90.000	C2	C1	H5	134.084
C2	C4	C3	90.000	C3	C1	H5	135.916
C4	C2	H6	135.916	C4	C3	H7	134.084

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: B3PW91/STO-3G

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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Number	Element	Mulliken
1	C	-0.085
2	C	-0.085
3	C	-0.085
4	C	-0.085
5	H	0.085
6	H	0.085
7	H	0.085
8	H	0.085

<r²>	57.410
(<r²>)^1/2	7.577

All results from a given calculation for C4H4 (cyclobutadiene)

using model chemistry: B3PW91/STO-3G

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)