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	-445.138487
Energy at 298.15K	-445.150229
Nuclear repulsion energy	245.278399

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	3160	2852	0.00
2	A₁	1486	1341	0.00
3	A₁	618	558	0.00
4	A₂	141	127	0.00
5	E	3218	2905	0.00
5	E	3218	2905	0.00
6	E	1629	1470	0.00
6	E	1629	1470	0.00
7	E	930	839	0.00
7	E	930	839	0.00
8	E	200	180	0.00
8	E	200	180	0.00
9	T₁	3219	2905	0.00
9	T₁	3219	2905	0.00
9	T₁	3219	2905	0.00
10	T₁	1625	1467	0.00
10	T₁	1625	1467	0.00
10	T₁	1625	1467	0.00
11	T₁	775	700	0.00
11	T₁	775	700	0.00
11	T₁	775	700	0.00
12	T₁	164	148	0.00
12	T₁	164	148	0.00
12	T₁	164	148	0.00
13	T₂	3222	2909	54.40
13	T₂	3222	2909	54.40
13	T₂	3222	2909	54.40
14	T₂	3158	2851	9.43
14	T₂	3158	2851	9.43
14	T₂	3158	2851	9.43
15	T₂	1643	1483	10.62
15	T₂	1643	1483	10.62
15	T₂	1643	1483	10.62
16	T₂	1478	1334	69.00
16	T₂	1478	1334	69.00
16	T₂	1478	1334	69.00
17	T₂	998	900	173.65
17	T₂	998	900	173.65
17	T₂	998	900	173.65
18	T₂	744	672	19.86
18	T₂	744	672	19.86
18	T₂	744	672	19.86
19	T₂	248	224	4.66
19	T₂	248	224	4.66
19	T₂	248	224	4.66

Unscaled Zero Point Vibrational Energy (zpe) 34591.5 cm^-1
Scaled (by 0.9026) Zero Point Vibrational Energy (zpe) 31222.3 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
0.10243	0.10243	0.10243

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	1.091	1.091	1.091
C3	-1.091	-1.091	1.091
C4	-1.091	1.091	-1.091
C5	1.091	-1.091	-1.091
H6	1.733	0.491	1.733
H7	1.733	1.733	0.491
H8	0.491	1.733	1.733
H9	-1.733	-1.733	0.491
H10	-0.491	-1.733	1.733
H11	-1.733	-0.491	1.733
H12	-1.733	0.491	-1.733
H13	-1.733	1.733	-0.491
H14	-0.491	1.733	-1.733
H15	1.733	-1.733	-0.491
H16	0.491	-1.733	-1.733
H17	1.733	-0.491	-1.733

Atom - Atom Distances (Å)

	Si1	C2	C3	C4	C5	H6	H7	H8	H9	H10	H11	H12	H13	H14	H15	H16	H17
Si1		1.8892	1.8892	1.8892	1.8892	2.4992	2.4992	2.4992	2.4992	2.4992	2.4992	2.4992	2.4992	2.4992	2.4992	2.4992	2.4992
C2	1.8892		3.0850	3.0850	3.0850	1.0883	1.0883	1.0883	4.0379	3.2994	3.2994	4.0379	3.2994	3.2994	3.2994	4.0379	3.2994
C3	1.8892	3.0850		3.0850	3.0850	3.2994	4.0379	3.2994	1.0883	1.0883	1.0883	3.2994	3.2994	4.0379	3.2994	3.2994	4.0379
C4	1.8892	3.0850	3.0850		3.0850	4.0379	3.2994	3.2994	3.2994	4.0379	3.2994	1.0883	1.0883	1.0883	4.0379	3.2994	3.2994
C5	1.8892	3.0850	3.0850	3.0850		3.2994	3.2994	4.0379	3.2994	3.2994	4.0379	3.2994	4.0379	3.2994	1.0883	1.0883	1.0883
H6	2.4992	1.0883	3.2994	4.0379	3.2994		1.7564	1.7564	4.3009	3.1447	3.6020	4.9011	4.3009	4.3009	3.1447	4.3009	3.6020
H7	2.4992	1.0883	4.0379	3.2994	3.2994	1.7564		1.7564	4.9011	4.3009	4.3009	4.3009	3.6020	3.1447	3.6020	4.3009	3.1447
H8	2.4992	1.0883	3.2994	3.2994	4.0379	1.7564	1.7564		4.3009	3.6020	3.1447	4.3009	3.1447	3.6020	4.3009	4.9011	4.3009
H9	2.4992	4.0379	1.0883	3.2994	3.2994	4.3009	4.9011	4.3009		1.7564	1.7564	3.1447	3.6020	4.3009	3.6020	3.1447	4.3009
H10	2.4992	3.2994	1.0883	4.0379	3.2994	3.1447	4.3009	3.6020	1.7564		1.7564	4.3009	4.3009	4.9011	3.1447	3.6020	4.3009
H11	2.4992	3.2994	1.0883	3.2994	4.0379	3.6020	4.3009	3.1447	1.7564	1.7564		3.6020	3.1447	4.3009	4.3009	4.3009	4.9011
H12	2.4992	4.0379	3.2994	1.0883	3.2994	4.9011	4.3009	4.3009	3.1447	4.3009	3.6020		1.7564	1.7564	4.3009	3.1447	3.6020
H13	2.4992	3.2994	3.2994	1.0883	4.0379	4.3009	3.6020	3.1447	3.6020	4.3009	3.1447	1.7564		1.7564	4.9011	4.3009	4.3009
H14	2.4992	3.2994	4.0379	1.0883	3.2994	4.3009	3.1447	3.6020	4.3009	4.9011	4.3009	1.7564	1.7564		4.3009	3.6020	3.1447
H15	2.4992	3.2994	3.2994	4.0379	1.0883	3.1447	3.6020	4.3009	3.6020	3.1447	4.3009	4.3009	4.9011	4.3009		1.7564	1.7564
H16	2.4992	4.0379	3.2994	3.2994	1.0883	4.3009	4.3009	4.9011	3.1447	3.6020	4.3009	3.1447	4.3009	3.6020	1.7564		1.7564
H17	2.4992	3.2994	4.0379	3.2994	1.0883	3.6020	3.1447	4.3009	4.3009	4.3009	4.9011	3.6020	4.3009	3.1447	1.7564	1.7564

picture of tetramethylsilane state 1 conformation 1

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
Si1	C2	H6	111.285	Si1	C2	H7	111.285
Si1	C2	H8	111.285	Si1	C3	H9	111.285
Si1	C3	H10	111.285	Si1	C3	H11	111.285
Si1	C4	H12	111.285	Si1	C4	H13	111.285
Si1	C4	H14	111.285	Si1	C5	H15	111.285
Si1	C5	H16	111.285	Si1	C5	H17	111.285
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	107.598	H6	C2	H8	107.598
H7	C2	H8	107.598	H9	C3	H10	107.598
H9	C3	H11	107.598	H10	C3	H11	107.598
H12	C4	H13	107.598	H12	C4	H14	107.598
H13	C4	H14	107.598	H15	C5	H16	107.598
H15	C5	H17	107.598	H16	C5	H17	107.598

Electronic energy levels

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

Number	Element	Mulliken
1	Si	1.545
2	C	-0.968
3	C	-0.968
4	C	-0.968
5	C	-0.968
6	H	0.194
7	H	0.194
8	H	0.194
9	H	0.194
10	H	0.194
11	H	0.194
12	H	0.194
13	H	0.194
14	H	0.194
15	H	0.194
16	H	0.194
17	H	0.194

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	-42.780	0.000	0.000
y	0.000	-42.780	0.000
z	0.000	0.000	-42.780

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	8.376	0.000	0.000
y	0.000	8.376	0.000
z	0.000	0.000	8.376

<r²> (average value of r²) Å²

<r²>	0.000
(<r²>)^1/2	0.000

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)