All results from a given calculation for C₄H₄ (cyclobutadiene)

Energy calculated at B3LYP/6-31G*

	hartrees
Energy at 0K	-154.675463
Energy at 298.15K	-154.678488
HF Energy	-154.675463
Nuclear repulsion energy	98.661075

The energy at 298.15K was derived from the energy at 0K and an integrated heat capacity that used the calculated vibrational frequencies.

Vibrational Frequencies calculated at B3LYP/6-31G*

Mode Number	Symmetry	Frequency (cm-1)	Scaled Frequency (cm-1)	IR Intensities (km mol-1)	Raman Act (Å4/u)	Dep P	Dep U
1	Ag	3264	3134	0.00
2	Ag	1646	1580	0.00
3	Ag	1121	1077	0.00
4	Ag	963	925	0.00
5	Au	871	836	0.00
6	Au	543	522	0.00
7	B1g	841	808	0.00
8	B1u	3253	3124	31.66
9	B1u	1658	1592	3.27
10	B1u	1070	1027	0.03
11	B2g	588	565	0.00
12	B2u	3232	3104	17.21
13	B2u	1274	1223	33.43
14	B2u	712	684	7.15
15	B3g	3216	3088	0.00
16	B3g	1184	1137	0.00
17	B3g	846	813	0.00
18	B3u	586	563	113.17

Unscaled Zero Point Vibrational Energy (zpe) 13433.3 cm^-1
Scaled (by 0.9603) Zero Point Vibrational Energy (zpe) 12900.0 cm^-1
See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.

Rotational Constants (cm^-1) from geometry optimized at B3LYP/6-31G*

A	B	C
0.56719	0.42593	0.24326

See section I.F.4 to change rotational constant units

Geometric Data calculated at B3LYP/6-31G*

Point Group is D_2h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.667	0.789
C2	0.000	0.667	-0.789
C3	0.000	-0.667	0.789
C4	0.000	-0.667	-0.789
H5	0.000	1.439	1.550
H6	0.000	1.439	-1.550
H7	0.000	-1.439	1.550
H8	0.000	-1.439	-1.550

Atom - Atom Distances (Å)

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.5782	1.3346	2.0669	1.0839	2.4634	2.2396	3.1479
C2	1.5782		2.0669	1.3346	2.4634	1.0839	3.1479	2.2396
C3	1.3346	2.0669		1.5782	2.2396	3.1479	1.0839	2.4634
C4	2.0669	1.3346	1.5782		3.1479	2.2396	2.4634	1.0839
H5	1.0839	2.4634	2.2396	3.1479		3.1005	2.8781	4.2304
H6	2.4634	1.0839	3.1479	2.2396	3.1005		4.2304	2.8781
H7	2.2396	3.1479	1.0839	2.4634	2.8781	4.2304		3.1005
H8	3.1479	2.2396	2.4634	1.0839	4.2304	2.8781	3.1005

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle		atom1	atom2	atom3	angle
C1	C2	C4	90.000		C1	C2	H6	134.603
C1	C3	C4	90.000		C1	C3	H7	135.397
C2	C1	C3	90.000		C2	C1	H5	134.603
C2	C4	C3	90.000		C3	C1	H5	135.397
C4	C2	H6	135.397		C4	C3	H7	134.603

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at B3LYP/6-31G* Charges (e)

Number	Element	Mulliken	CHELPG	AIM	ESP
1	C	-0.135
2	C	-0.135
3	C	-0.135
4	C	-0.135
5	H	0.135
6	H	0.135
7	H	0.135
8	H	0.135

Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)

	x	y	z	Total
	0.000	0.000	0.000	0.000
CHELPG
AIM
ESP

Electric Quadrupole moment
Quadrupole components in D Å

Primitive   x y z x -25.912 0.000 0.000 y 0.000 -20.597 0.000 z 0.000 0.000 -21.653

Traceless   x y z x -4.786 0.000 0.000 y 0.000 3.186 0.000 z 0.000 0.000 1.601

Polar 3z2-r2 3.201 x2-y2 -5.315 xy 0.000 xz 0.000 yz 0.000

Polarizabilities
Components of the polarizability tensor.
Units are ų (Angstrom cubed)
Change units.

	x	y	z
x	2.298	0.000	0.000
y	0.000	6.927	0.000
z	0.000	0.000	5.561

<r²> (average value of r²) Ų

<r2>	57.719
(<r2>)1/2	7.597

Energy calculated at B3LYP/6-31G*

	hartrees
Energy at 0K	-154.606992
Energy at 298.15K
HF Energy	-154.606992
Nuclear repulsion energy	99.249621

The energy at 298.15K was derived from the energy at 0K and an integrated heat capacity that used the calculated vibrational frequencies.

Vibrational Frequencies calculated at B3LYP/6-31G*

Rotational Constants (cm^-1) from geometry optimized at B3LYP/6-31G*

A	B	C
0.49877	0.49877	0.24939

See section I.F.4 to change rotational constant units

Geometric Data calculated at B3LYP/6-31G*

Point Group is D_4h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	1.019	0.000
C2	1.019	0.000	0.000
C3	-1.019	0.000	0.000
C4	0.000	-1.019	0.000
H5	0.000	2.101	0.000
H6	2.101	0.000	0.000
H7	-2.101	0.000	0.000
H8	0.000	-2.101	0.000

Atom - Atom Distances (Å)

	C1	C2	C3	C4	H5	H6	H7	H8
C1		1.4405	1.4405	2.0372	1.0823	2.3348	2.3348	3.1195
C2	1.4405		2.0372	1.4405	2.3348	1.0823	3.1195	2.3348
C3	1.4405	2.0372		1.4405	2.3348	3.1195	1.0823	2.3348
C4	2.0372	1.4405	1.4405		3.1195	2.3348	2.3348	1.0823
H5	1.0823	2.3348	2.3348	3.1195		2.9712	2.9712	4.2019
H6	2.3348	1.0823	3.1195	2.3348	2.9712		4.2019	2.9712
H7	2.3348	3.1195	1.0823	2.3348	2.9712	4.2019		2.9712
H8	3.1195	2.3348	2.3348	1.0823	4.2019	2.9712	2.9712

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle		atom1	atom2	atom3	angle
C1	C2	C4	90.000		C1	C2	H6	135.000
C1	C3	C4	90.000		C1	C3	H7	135.000
C2	C1	C3	90.000		C2	C1	H5	135.000
C2	C4	C3	90.000		C3	C1	H5	135.000
C4	C2	H6	135.000		C4	C3	H7	135.000

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at B3LYP/6-31G* Charges (e)

Number	Element	Mulliken	CHELPG	AIM	ESP
1	C	-0.292
2	C	0.013
3	C	0.013
4	C	-0.292
5	H	0.108
6	H	0.171
7	H	0.171
8	H	0.108

Electric dipole moments

Electric Quadrupole moment
Quadrupole components in D Å

Primitive   x y z x -17.093 0.000 0.000 y 0.000 -25.361 0.000 z 0.000 0.000 -26.249

Traceless   x y z x 8.711 0.000 0.000 y 0.000 -3.690 0.000 z 0.000 0.000 -5.022

Polar 3z2-r2 -10.043 x2-y2 8.267 xy 0.000 xz 0.000 yz 0.000

Polarizabilities
Components of the polarizability tensor.
Units are ų (Angstrom cubed)
Change units.

	x	y	z
x	6.675	0.000	0.000
y	0.000	7.037	0.000
z	0.000	0.000	2.322

<r²> (average value of r²) Ų

<r2>	56.860
(<r2>)1/2	7.541