Différences entre les versions de « VBTutorial3 »

De Workshops
Aller à la navigation Aller à la recherche
 
(4 versions intermédiaires par 2 utilisateurs non affichées)
Ligne 1 : Ligne 1 :
[[VB_workshop_tutorials_program|<< Return to the program]]
+
[[VB_tutorial|<<< VB tutorials main page]]
  
  
Ligne 31 : Ligne 31 :
 
## minimal structures for reactant;
 
## minimal structures for reactant;
 
## minimal structures for product.
 
## minimal structures for product.
# How would you define your different fragment orbitals for this calculation (''$frag'' section) ? You will find the answer for this case is in the [[Recommended_definition_for_the_orbital_blocks "recommended definition for the orbital blocks" section of the "practical for BOVB calculations" document]]
+
# How would you define your different fragment orbitals for this calculation (''$frag'' section) ? You will find the answer for this case is in the [[General_guidelines_for_BOVB_calculations#Recommended_definition_for_the_orbital_blocks|"recommended definition for the orbital blocks" section of the "practical for BOVB calculations" document]]
 
# Perform <math>\pi</math>-D-BOVB calculation for reactant [[General_guidelines_for_BOVB_calculations#High_symmetry_case:|(see "high symmetry cases" here)]]:
 
# Perform <math>\pi</math>-D-BOVB calculation for reactant [[General_guidelines_for_BOVB_calculations#High_symmetry_case:|(see "high symmetry cases" here)]]:
 
## Perform all-structure <math>\pi</math>-D-BOVB calculation as following:
 
## Perform all-structure <math>\pi</math>-D-BOVB calculation as following:
Ligne 48 : Ligne 48 :
 
# Compute the Barrier height of the <math>\textrm{S}_{\textrm{N}}2</math> reaction in both vacuum and solution. See the difference of the barrier heights, and find out the reason.
 
# Compute the Barrier height of the <math>\textrm{S}_{\textrm{N}}2</math> reaction in both vacuum and solution. See the difference of the barrier heights, and find out the reason.
 
# Compare the energies of reactant and product structures at reactant and transition state geometries, in both vacuum and solution. What's the difference of the energies at different points? Why?
 
# Compare the energies of reactant and product structures at reactant and transition state geometries, in both vacuum and solution. What's the difference of the energies at different points? Why?
# Compute the resonance energies at both reactant and transition state points, see the difference of the resonance energies.
+
# Compute the resonance energy at the crossing point of diabatic curves state points in vacuum.
  
 
{| class="collapsible collapsed wikitable"
 
{| class="collapsible collapsed wikitable"
Ligne 144 : Ligne 144 :
 
! scope="col" | VBSCF
 
! scope="col" | VBSCF
 
! scope="col" | BOVB
 
! scope="col" | BOVB
! scope="col" | VBSCF/PCM
 
 
! scope="col" | BOVB/PCM
 
! scope="col" | BOVB/PCM
 
|-  
 
|-  
 
! scope="row"    | All Structures
 
! scope="row"    | All Structures
| -36.98034 ||-37.02508 || -37.06980 || -37.11346  
+
| -36.98034 ||-37.02508 || -37.11346  
 
|-
 
|-
 
! scope="row" | Reactant
 
! scope="row" | Reactant
| -36.95812 || -36.97494 || -37.05258 || -37.06909
+
| -36.95984 || -36.98719 || -37.07951
 
|-
 
|-
 
! scope="row" | Product
 
! scope="row" | Product
| -36.95812 ||-36.97494 ||-37.05258 || -37.06910
+
| -36.95984 ||-36.98718  || -37.07949
 
|-
 
|-
 
! scope="row"      | Resonance Energy
 
! scope="row"      | Resonance Energy
| 13.9 || 31.5 || 10.8 || 27.8
+
| 12.9 || 23.8 || 21.3
 
|}
 
|}
 
</center>
 
</center>
  
  
|}
 
  
|}
 
  
 
{| class="collapsible collapsed wikitable"
 
{| class="collapsible collapsed wikitable"
Ligne 181 : Ligne 178 :
 
|-
 
|-
 
|
 
|
 +
 
=====Weights of Structures=====
 
=====Weights of Structures=====
 
<center>
 
<center>

Dernière version du 18 janvier 2013 à 15:56

<<< VB tutorials main page


Valence Bond State correlation diagrams

Exercise 1 : Computation of state correlation Diagrams for a 3 centers / 4 electrons system

In this exercise the <math>\textrm{S}_{\textrm{N}}2</math> reaction Cl<math>{}^{-}</math> + CH<math>{}_3</math>Cl -> ClCH<math>{}_3</math> + Cl<math>{}^{-}</math> will be studied in both vacuum and solution. Valence Bond State Correlation Diagrams (VBSCD) will be constructed at <math>\pi</math>-D-BOVB level. There are two parts in this exercise: basic part and optional part. The basic part is performed with MCP-DZP basis set in which the inner orbitals in Cl and C are described with MCP pseudo potential. The optional part is performed with 6-31+G* basis set, using the general specification for the xmvb input (expert users). Only reactant and transition state will be computed in this exercise, which is sufficient to build the VBSCD diagrams.