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	hartrees
Energy at 0K	-154.265771
Energy at 298.15K	-154.268586
HF Energy	-153.656833
Nuclear repulsion energy	97.368338

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)
1	A_g	3245	3173
2	A_g	1514	1481
3	A_g	1105	1080
4	A_g	932	911
5	A_u	693	677
6	A_u	471	460
7	B_1g	769	752
8	B_1u	3232	3161
9	B_1u	1542	1507
10	B_1u	1032	1009
11	B_2g	507	496
12	B_2u	3214	3143
13	B_2u	1247	1219
14	B_2u	708	693
15	B_3g	3199	3128
16	B_3g	1146	1121
17	B_3g	847	828
18	B_3u	548	536

Atom	y (Å)	z (Å)
C1	0.683	0.793
C2	0.683	-0.793
C3	-0.683	0.793
C4	-0.683	-0.793
H5	1.457	1.566
H6	1.457	-1.566
H7	-1.457	1.566
H8	-1.457	-1.566

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5850	1.3664	2.0927	1.0941	2.4824	2.2755	3.1849
C2	1.5850		2.0927	1.3664	2.4824	1.0941	3.1849	2.2755
C3	1.3664	2.0927		1.5850	2.2755	3.1849	1.0941	2.4824
C4	2.0927	1.3664	1.5850		3.1849	2.2755	2.4824	1.0941
H5	1.0941	2.4824	2.2755	3.1849		3.1327	2.9134	4.2781
H6	2.4824	1.0941	3.1849	2.2755	3.1327		4.2781	2.9134
H7	2.2755	3.1849	1.0941	2.4824	2.9134	4.2781		3.1327
H8	3.1849	2.2755	2.4824	1.0941	4.2781	2.9134	3.1327

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	135.013
C1	C3	C4	90.000	C1	C3	H7	134.987
C2	C1	C3	90.000	C2	C1	H5	135.013
C2	C4	C3	90.000	C3	C1	H5	134.987
C4	C2	H6	134.987	C4	C3	H7	135.013

All results from a given calculation for C₄H₄ (cyclobutadiene)

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

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)