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	hartrees
Energy at 0K	-154.212907
Energy at 298.15K	-154.215801
HF Energy	-153.658698
Nuclear repulsion energy	97.830523

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A_g	3289	3188	0.00
2	A_g	1559	1511	0.00
3	A_g	1119	1085	0.00
4	A_g	963	933	0.00
5	A_u	734	711	0.00
6	A_u	482	468	0.00
7	B_1g	813	788	0.00
8	B_1u	3278	3177	14.40
9	B_1u	1564	1516	6.02
10	B_1u	1048	1016	0.13
11	B_2g	528	512	0.00
12	B_2u	3257	3157	7.75
13	B_2u	1252	1214	31.93
14	B_2u	718	695	8.16
15	B_3g	3243	3143	0.00
16	B_3g	1168	1132	0.00
17	B_3g	843	817	0.00
18	B_3u	552	535	140.79

Atom	y (Å)	z (Å)
C1	0.679	0.789
C2	0.679	-0.789
C3	-0.679	0.789
C4	-0.679	-0.789
H5	1.449	1.562
H6	1.449	-1.562
H7	-1.449	1.562
H8	-1.449	-1.562

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5781	1.3586	2.0824	1.0905	2.4734	2.2642	3.1710
C2	1.5781		2.0824	1.3586	2.4734	1.0905	3.1710	2.2642
C3	1.3586	2.0824		1.5781	2.2642	3.1710	1.0905	2.4734
C4	2.0824	1.3586	1.5781		3.1710	2.2642	2.4734	1.0905
H5	1.0905	2.4734	2.2642	3.1710		3.1230	2.8981	4.2606
H6	2.4734	1.0905	3.1710	2.2642	3.1230		4.2606	2.8981
H7	2.2642	3.1710	1.0905	2.4734	2.8981	4.2606		3.1230
H8	3.1710	2.2642	2.4734	1.0905	4.2606	2.8981	3.1230

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
C1	C2	C4	90.000	C1	C2	H6	135.101
C1	C3	C4	90.000	C1	C3	H7	134.899
C2	C1	C3	90.000	C2	C1	H5	135.101
C2	C4	C3	90.000	C3	C1	H5	134.899
C4	C2	H6	134.899	C4	C3	H7	135.101

All results from a given calculation for C₄H₄ (cyclobutadiene)

using model chemistry: MP2=FULL/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: MP2=FULL/aug-cc-pVDZ

States and conformations

All results from a given calculation for C₄H₄ (cyclobutadiene)