CCCBDB calculation results Page

State	Conformation	minimum conformation	conformer description	state description
1	1	yes	TD	¹A₁

Energy calculated at HF/3-21G

	hartrees
Energy at 0K	-445.046609
Energy at 298.15K	-445.058248
Nuclear repulsion energy	242.567761

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 HF/3-21G

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	A₁	3178	2878	0.00
2	A₁	1477	1338	0.00
3	A₁	596	539	0.00
4	A₂	128	116	0.00
5	E	3244	2937	0.00
5	E	3244	2937	0.00
6	E	1628	1474	0.00
6	E	1628	1474	0.00
7	E	948	859	0.00
7	E	948	859	0.00
8	E	193	175	0.00
8	E	193	175	0.00
9	T₁	3244	2938	0.00
9	T₁	3244	2938	0.00
9	T₁	3244	2938	0.00
10	T₁	1624	1470	0.00
10	T₁	1624	1470	0.00
10	T₁	1624	1470	0.00
11	T₁	806	730	0.00
11	T₁	806	730	0.00
11	T₁	806	730	0.00
12	T₁	150	136	0.00
12	T₁	150	136	0.00
12	T₁	150	136	0.00
13	T₂	3247	2940	44.43
13	T₂	3247	2940	44.43
13	T₂	3247	2940	44.43
14	T₂	3176	2876	12.16
14	T₂	3176	2876	12.16
14	T₂	3176	2876	12.16
15	T₂	1642	1487	14.56
15	T₂	1642	1487	14.56
15	T₂	1642	1487	14.56
16	T₂	1464	1326	54.07
16	T₂	1464	1326	54.07
16	T₂	1464	1326	54.07
17	T₂	1005	910	163.00
17	T₂	1005	910	163.00
17	T₂	1005	910	163.00
18	T₂	734	664	20.86
18	T₂	734	664	20.86
18	T₂	734	664	20.86
19	T₂	240	218	6.40
19	T₂	240	218	6.40
19	T₂	240	218	6.40

Unscaled Zero Point Vibrational Energy (zpe) 34698.7 cm^-1
Scaled (by 0.9056) Zero Point Vibrational Energy (zpe) 31423.2 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 HF/3-21G

A	B	C
0.09973	0.09973	0.09973

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

Geometric Data calculated at HF/3-21G

Point Group is T_d

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
Si1	0.000	0.000	0.000
C2	1.108	1.108	1.108
C3	-1.108	-1.108	1.108
C4	-1.108	1.108	-1.108
C5	1.108	-1.108	-1.108
H6	1.746	0.504	1.746
H7	1.746	1.746	0.504
H8	0.504	1.746	1.746
H9	-1.746	-1.746	0.504
H10	-0.504	-1.746	1.746
H11	-1.746	-0.504	1.746
H12	-1.746	0.504	-1.746
H13	-1.746	1.746	-0.504
H14	-0.504	1.746	-1.746
H15	1.746	-1.746	-0.504
H16	0.504	-1.746	-1.746
H17	1.746	-0.504	-1.746

Atom - Atom Distances (Å)

	Si1	C2	C3	C4	C5	H6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17
Si1		1.9187	1.9187	1.9187	1.9187	2.5208	2.5208	2.5208	2.5208	2.5208	2.5208	2.5208	2.5208	2.5208	2.5208	2.5208	2.5208
C2	1.9187		3.1331	3.1331	3.1331	1.0865	1.0865	1.0865	4.0814	3.3395	3.3395	4.0814	3.3395	3.3395	3.3395	4.0814	3.3395
C3	1.9187	3.1331		3.1331	3.1331	3.3395	4.0814	3.3395	1.0865	1.0865	1.0865	3.3395	3.3395	4.0814	3.3395	3.3395	4.0814
C4	1.9187	3.1331	3.1331		3.1331	4.0814	3.3395	3.3395	3.3395	4.0814	3.3395	1.0865	1.0865	1.0865	4.0814	3.3395	3.3395
C5	1.9187	3.1331	3.1331	3.1331		3.3395	3.3395	4.0814	3.3395	3.3395	4.0814	3.3395	4.0814	3.3395	1.0865	1.0865	1.0865
H6	2.5208	1.0865	3.3395	4.0814	3.3395		1.7571	1.7571	4.3370	3.1827	3.6355	4.9398	4.3370	4.3370	3.1827	4.3370	3.6355
H7	2.5208	1.0865	4.0814	3.3395	3.3395	1.7571		1.7571	4.9398	4.3370	4.3370	4.3370	3.6355	3.1827	3.6355	4.3370	3.1827
H8	2.5208	1.0865	3.3395	3.3395	4.0814	1.7571	1.7571		4.3370	3.6355	3.1827	4.3370	3.1827	3.6355	4.3370	4.9398	4.3370
H9	2.5208	4.0814	1.0865	3.3395	3.3395	4.3370	4.9398	4.3370		1.7571	1.7571	3.1827	3.6355	4.3370	3.6355	3.1827	4.3370
H10	2.5208	3.3395	1.0865	4.0814	3.3395	3.1827	4.3370	3.6355	1.7571		1.7571	4.3370	4.3370	4.9398	3.1827	3.6355	4.3370
H11	2.5208	3.3395	1.0865	3.3395	4.0814	3.6355	4.3370	3.1827	1.7571	1.7571		3.6355	3.1827	4.3370	4.3370	4.3370	4.9398
H12	2.5208	4.0814	3.3395	1.0865	3.3395	4.9398	4.3370	4.3370	3.1827	4.3370	3.6355		1.7571	1.7571	4.3370	3.1827	3.6355
H13	2.5208	3.3395	3.3395	1.0865	4.0814	4.3370	3.6355	3.1827	3.6355	4.3370	3.1827	1.7571		1.7571	4.9398	4.3370	4.3370
H14	2.5208	3.3395	4.0814	1.0865	3.3395	4.3370	3.1827	3.6355	4.3370	4.9398	4.3370	1.7571	1.7571		4.3370	3.6355	3.1827
H15	2.5208	3.3395	3.3395	4.0814	1.0865	3.1827	3.6355	4.3370	3.6355	3.1827	4.3370	4.3370	4.9398	4.3370		1.7571	1.7571
H16	2.5208	4.0814	3.3395	3.3395	1.0865	4.3370	4.3370	4.9398	3.1827	3.6355	4.3370	3.1827	4.3370	3.6355	1.7571		1.7571
H17	2.5208	3.3395	4.0814	3.3395	1.0865	3.6355	3.1827	4.3370	4.3370	4.3370	4.9398	3.6355	4.3370	3.1827	1.7571	1.7571

picture of tetramethylsilane state 1 conformation 1

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
Si1	C2	H6	110.981	Si1	C2	H7	110.981
Si1	C2	H8	110.981	Si1	C3	H9	110.981
Si1	C3	H10	110.981	Si1	C3	H11	110.981
Si1	C4	H12	110.981	Si1	C4	H13	110.981
Si1	C4	H14	110.981	Si1	C5	H15	110.981
Si1	C5	H16	110.981	Si1	C5	H17	110.981
C2	Si1	C3	109.471	C2	Si1	C4	109.471
C2	Si1	C5	109.471	C3	Si1	C4	109.471
C3	Si1	C5	109.471	C4	Si1	C5	109.471
H6	C2	H7	107.921	H6	C2	H8	107.921
H7	C2	H8	107.921	H9	C3	H10	107.921
H9	C3	H11	107.921	H10	C3	H11	107.921
H12	C4	H13	107.921	H12	C4	H14	107.921
H13	C4	H14	107.921	H15	C5	H16	107.921
H15	C5	H17	107.921	H16	C5	H17	107.921

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at HF/3-21G Charges (e)

Number	Element	Mulliken
1	Si	1.841
2	C	-1.076
3	C	-1.076
4	C	-1.076
5	C	-1.076
6	H	0.205
7	H	0.205
8	H	0.205
9	H	0.205
10	H	0.205
11	H	0.205
12	H	0.205
13	H	0.205
14	H	0.205
15	H	0.205
16	H	0.205
17	H	0.205

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	-43.515	0.000	0.000
y	0.000	-43.515	0.000
z	0.000	0.000	-43.515

Traceless
	x	y	z
x	0.000	0.000	0.000
y	0.000	0.000	0.000
z	0.000	0.000	0.000

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

Polarizabilities
Components of the polarizability tensor.
Units are Å³ (Angstrom cubed)
Change units.

	x	y	z
x	8.675	0.000	0.000
y	0.000	8.675	0.000
z	0.000	0.000	8.675

<r²> (average value of r²) Å²

<r²>	191.782
(<r²>)^1/2	13.849

All results from a given calculation for Si(CH₃)₄ (tetramethylsilane)

using model chemistry: HF/3-21G

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 Si(CH3)4 (tetramethylsilane)

using model chemistry: HF/3-21G

States and conformations

All results from a given calculation for Si(CH₃)₄ (tetramethylsilane)