4-coordinate: tetrahedral (p-block element, 2 lone pairs)

[(μ₂-Se)(TlSe₂)]₂⁶⊖

Formula Unicode styled: 
[(μ₂-Se)(TlSe₂)]₂⁶⊖
Compound name(s): 
bis-[diselenido-(μ₂-selenido)-thallium (3-)]
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2O-IIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[C₆(SeBuᵗ)₆]

Formula Unicode styled: 
[C₆(SeBuᵗ)₆]
Compound name(s): 
hexakis(t-butylselanyl)benzene
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[C₆(SePh)₆]

Formula Unicode styled: 
[C₆(SePh)₆]
Compound name(s): 
hexakis(phenylseleno)benzene
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[(μ₂-Se)₂(WSe₂)₂]₂²⊖

Formula Unicode styled: 
[(μ₂-Se)₂(WSe₂)₂]₂²⊖
Compound name(s): 
bis-[(μ₂-seleno)-{diselenido-tungsten}(1-)]
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2O-IIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[(μ₂-Se)₂{W(CNBuᵗ(SeC₆H₃Mes₂)}₂]₂

Formula Unicode styled: 
[(μ₂-Se)₂{W(CNBuᵗ(SeC₆H₃Mes₂)}₂]₂
Compound name(s): 
bis(μ₂-seleno)-bis{(t-butylisocyano)-bis(mesitylphenylselenolato)-tungsten}]
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2O-IIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[(μ₂-Se){Mo(Se)₂O}]₂²⊖

Formula Unicode styled: 
[(μ₂-Se){Mo(Se)₂O}]₂²⊖
Compound name(s): 
bis-[(μ₂-selenido)-bis{(diselenido)-oxo-molybdenum}(1-)]
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2O-IIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se]₇

Formula Unicode styled: 
[Se]₇
Compound name(s): 
cyclo-heptaselenium
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OOE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se(Sn(Se)₂]₂⁴⊖

Formula Unicode styled: 
[Se(Sn(Se)₂]₂⁴⊖
Compound name(s): 
bis-[(μ₂-selenido)-diselenolato-tin(2-)]
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2O-IIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se₃(Ph)₃(μ₃-CH)]

Formula Unicode styled: 
[Se₃(Ph)₃(μ₃-CH)]
Compound name(s): 
tris(phenylseleno)methane
Central atom: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se(μ₂-CPh₂)]₂

Formula Unicode styled: 
[Se(μ₂-CPh₂)]₂
Compound name(s): 
bis-[(μ₂-diphenylcarbon)-selenium]
Central atom: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C1OIIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se(SO₂Tol)]₂

Formula Unicode styled: 
[Se(SO₂Tol)]₂
Compound name(s): 
bis[(p-tolylsulfonyl)-selenium]
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se(SnBuᵗ₂)]₂

Formula Unicode styled: 
[Se(SnBuᵗ₂)]₂
Compound name(s): 
bis-[(μ₂-di-t-butyl-tin)selenium]
Central atom: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C1O-IIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se₄{(CH₂)₄}₂{(CH₂)₃}₂]

Formula Unicode styled: 
[Se₄{(CH₂)₄}₂{(CH₂)₃}₂]
Compound name(s): 
1,4,8,11-tetraselenacyclotetradecane
Central atom: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se₆{(CH₂)₃}₆]

Formula Unicode styled: 
[Se₆{(CH₂)₃}₆]
Compound name(s): 
1,5,9,13,17,21-hexaselenacyclotetracosane
Central atom: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se₆(μ₂-CH₂)₃{(CH₂)₃}₃]

Formula Unicode styled: 
[Se₆(μ₂-CH₂)₃{(CH₂)₃}₃]
Compound name(s): 
1,3,7,9,13,15-hexaselenacyclo-octadecane
Central atom: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se(S)]₂²⊖

Formula Unicode styled: 
[Se(S)]₂²⊖
Compound name(s): 
tetraselenium(2-)
Central atom: 
Attached groups: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se₄(μ₂-CH₂)₂{(CH₂)₃}₂]

Formula Unicode styled: 
[Se₄(μ₂-CH₂)₂{(CH₂)₃}₂]
Compound name(s): 
1,3,7,9-tetraseleno-cyclododecane
Central atom: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se(Me)(=C(NH₂)₂)]⊕

Formula Unicode styled: 
[Se(Me)(=C(NH₂)₂)]⊕
Compound name(s): 
methyl-diaminomethylidene-selenium(1+)
Central atom: 
Charge on central atom: 
1
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V4C2OIVE8B3Z0L0X3»
[MLXZ]𝘲 class: 
[MX3]+
MLXZ class (ENC, equivalent neutral class): 
MX2Z1

[

Formula Unicode styled: 
[(Se₃){Ti(η⁵-C₅H₅)₂}]
Compound name(s): 
(pentaselenido-Se,Se')-{bis(η⁵-cyclopentadienyl)-titanium}
Central atom: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2O-IE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2

[Se(SO₃-κS)(SSO₃-κS)]²⊖

Formula Unicode styled: 
[Se(SO₃-κS)(SSO₃-κS)]²⊖
Compound name(s): 
(sulphato-κS)-(thiosulphato-κS)-selenium(2-)
selenotetrathionate
Central atom: 
Charge on central atom: 
0
Compound type: 
Valence Number (VN) = 𝘹 + 2𝘻 : 
Oxidation Number (ON) (Roman numerals): 
Coordination Number (CN, sum of attached group denticities): 
Electron Number (EN) = 𝘮 + 𝘹 +2𝘭: 
Summary of calculated classifications: 
Se«V2C2OIIE8B2Z0L0X2»
[MLXZ]𝘲 class: 
[MX2]
MLXZ class (ENC, equivalent neutral class): 
MX2