Comp Chem 02 - Revision history

Bes at 22:09, 25 April 2020

2020-04-25T22:09:17Z

2020-04-16T14:08:23Z

Charge/Multiplicity

2020-04-16T13:42:57Z

Charge/Multiplicity

2020-04-16T13:42:38Z

Charge/Multiplicity

2020-04-16T13:39:53Z

Charge/Multiplicity

2020-04-16T13:33:37Z

Accurate

2020-04-16T13:31:59Z

Accurate

2020-04-16T13:31:01Z

Basic

2020-04-16T13:30:47Z

Routine

2020-04-16T13:30:03Z

Routine

← Older revision		Revision as of 14:08, 16 April 2020
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	Please do (now or email me with when you will have it done) the following exercise:		Please do (now or email me with when you will have it done) the following exercise:

−	[[WebMO_Basis_set_1\| Exercise 4: Exploring Effect of Basis Sets]]	+	[[WebMO_Basis_set_1\| Exercise 4: Exploring Effect of Theory and Basis Sets]]

← Older revision		Revision as of 13:42, 16 April 2020
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	Please do (now or email me with when you will have it done) the following exercise:		Please do (now or email me with when you will have it done) the following exercise:
		+
	[[WebMO_Basis_set_1\| Exercise 4: Exploring Effect of Basis Sets]]		[[WebMO_Basis_set_1\| Exercise 4: Exploring Effect of Basis Sets]]

← Older revision		Revision as of 13:42, 16 April 2020
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	:When using the graphical interface to "draw" the molecular structure, you are showing connectivity between the atoms. If electrons are added, the negative charge increases and the multiplicity also changes. So "charge and multiplicity accounts for electron configuration not well described by the molecular structure. Multiplicty is calculated as:		:When using the graphical interface to "draw" the molecular structure, you are showing connectivity between the atoms. If electrons are added, the negative charge increases and the multiplicity also changes. So "charge and multiplicity accounts for electron configuration not well described by the molecular structure. Multiplicty is calculated as:
	:::2S+1 where S is the number of unpaired electrons 1/2. For example, if an system has 2 unpaired electrons (like O<sub>2</sub> gas), the multiplicity is 2(2*1/2) +1 = 3 or triplet; radicals with one unpaired electron has a multiplicity of 2 or doublet.		:::2S+1 where S is the number of unpaired electrons 1/2. For example, if an system has 2 unpaired electrons (like O<sub>2</sub> gas), the multiplicity is 2(2*1/2) +1 = 3 or triplet; radicals with one unpaired electron has a multiplicity of 2 or doublet.
		+
		+	Please do (now or email me with when you will have it done) the following exercise:
		+	[[WebMO_Basis_set_1\| Exercise 4: Exploring Effect of Basis Sets]]

← Older revision		Revision as of 13:39, 16 April 2020
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	===Charge/Multiplicity===		===Charge/Multiplicity===
		+	:When using the graphical interface to "draw" the molecular structure, you are showing connectivity between the atoms. If electrons are added, the negative charge increases and the multiplicity also changes. So "charge and multiplicity accounts for electron configuration not well described by the molecular structure. Multiplicty is calculated as:
		+	:::2S+1 where S is the number of unpaired electrons 1/2. For example, if an system has 2 unpaired electrons (like O<sub>2</sub> gas), the multiplicity is 2(2*1/2) +1 = 3 or triplet; radicals with one unpaired electron has a multiplicity of 2 or doublet.

@@ Line 112: / Line 112: @@
 ====Accurate====
 :This basis set, ''Accurate: 6-311+G(2d,p)'' is an improvement over 6-31G(d) and is also a "split-valence" basis set with additional diffuse functions. 6-311+G(2d,p) means the core electrons are approximated by 6 Gaussian functions and the valence electrons are "split" into 3 separate types of valence electrons represented by 3, 1, and 1 Gaussians, with the addition of 2 d-orbitals and 1 p-orbibal to allow for even greater asymmetry in the solution.
 ===Charge/Multiplicity===

@@ Line 105: / Line 105: @@
 ====Basic====
-:This basis set, Basic: 3-21G is an improvement over STO-3G and is referred to as a "split-valance" basis set. This differs from STO-3G in that the valence electrons are treated differently than the core electrons...3-21G means the core electrons are approximated by 3 Gaussian functions and the valence electrons are "split" into "inner" valence electrons represented by 2 Gaussians and "outer" valence electrons represented by 1 Gaussian.
+:This basis set, ''Basic: 3-21G'' is an improvement over STO-3G and is referred to as a "split-valance" basis set. This differs from STO-3G in that the valence electrons are treated differently than the core electrons...3-21G means the core electrons are approximated by 3 Gaussian functions and the valence electrons are "split" into "inner" valence electrons represented by 2 Gaussians and "outer" valence electrons represented by 1 Gaussian.
 ====Routine====

@@ Line 108: / Line 108: @@
 ====Routine====
-:This basis set, Routine: 6-31G(d) is an improvement over 3-21G and is also a "split-valence" basis set with the addition of "diffuse functions" (d-orbitals). The additional of d-orbital allows for the wavefunctions to be "polarized" or asymmetric. 6-31G(d) means the core electrons are approximated by 6 Gaussian functions and the valence electrons are "split" into "inner" valence electrons represented by 3 Gaussians and "outer" valence electrons represented by 1 Gaussian, with the addition of d-orbitals to allow for asymmetry in the solution.
+:This basis set, ''Routine: 6-31G(d)'' is an improvement over 3-21G and is also a "split-valence" basis set with the addition of "diffuse functions" (d-orbitals). The additional of a d-orbital allows for the wavefunctions to be "polarized" or asymmetric. 6-31G(d) means the core electrons are approximated by 6 Gaussian functions and the valence electrons are "split" into "inner" valence electrons represented by 3 Gaussians and "outer" valence electrons represented by 1 Gaussian, with the addition of d-orbitals to allow for asymmetry in the solution.
 ====Accurate====