Presentation is loading. Please wait.

Presentation is loading. Please wait.

Molecular Models. Methodology: Modify Wavefunction.

Published byMakaila Fountain Modified over 9 years ago

Similar presentations

Presentation on theme: "Molecular Models. Methodology: Modify Wavefunction."— Presentation transcript:

1 Molecular Models

2 Methodology: Modify Wavefunction

3 Theory: Wavefunction

4 Computation: Basis Set AO TypeFunctional Forms s e -ar 2 Px x e -ar 2 Py y e -ar 2 Pz z e -ar 2 dx2dx2 x 2 e -ar 2 dy2dy2 y 2 e -ar 2 dz2dz2 z 2 e -ar 2 d xyxy e -ar 2 d xzxz e -ar 2 d yzyz e -ar 2

5 Computation: Basis Set Basis set # functions Basis set # functions Basis set # functions STO-3G56-31G96-311G13 3-21G96-31G*156-311G*18* 4-31G96-31+G*196-311+G*22*

6 Computation: Electron Correlation

7 Configuration Interaction (CI) unoccupied occupied

8 Moller Plesset (MP) Hartree-Fock close to Full Hamiltonian Perturbation

9 Computation: Computation Time

10 Results: Geometry Basis Bond Length Error (Å) Bond Angle Error (deg.) STO-3G0.0542.3 3-21G0.0163.8 3-21G(*)0.0173.3 6-31G*0.0141.5 6-31G**0.0141.8 6-311G**0.013-- Mean Absolute Errors for A-H bond parameters Basis Bond Length Error (Å) (single bonds) Bond Length Error (Å) (multipe bonds) Bond Angle Error (deg.) STO-3G0.0490.0171.3 3-21G0.0290.0121.0 3-21G(*)0.0290.0120.9 6-31G*0.0440.023-- 6-31G**0.0460.021-- 6-311G**0.0390.025-- Mean Errors for A-B bond parameters

11 Results: Geometry MoleculeCoordinateHFMP2CCSDMP4CCSD(T) Error in Bond Length (Å) H2OH2OO-H-0.0060.0050.0040.005 NH 3 N-H-0.0110.0020.0030.004 CH 4 C-H-0.0010.0030.0050.006 C2H2C2H2 C-H C-C -0.002 -0.012 0.006 0.024 0.007 0.016 0.008 0.025 0.008 0.023 CH 2 O C-H C=O -0.005 -0.015 0.003 0.022 0.004 0.015 0.008 0.023 0.006 0.021 HCN C-H C-N -0.003 -0.017 0.004 0.032 0.005 0.019 0.006 0.030 0.006 0.024 HCN N-H C-N -0.008 -0.010 0.007 0.025 0.006 0.017 0.007 0.031 0.008 0.024 CO 2 C-O-0.0150.0220.0120.0280.018 Average Abs. Error ()-0.0090.0130.0090.0150.013 Error in Bond Angle (deg.) H2OH2OH-O-H2.1-0.10.10.0 NH 3 H-N-H1.50.0-0.2-0.3-0.4 CH 2 0H-C-O-0.3-0.2 -0.6-0.2 Average Error (deg.)1.3-0.1 -0.3-0.2

12 Results: Geometry

13 Results: Energy

14 Methodsto-3g3-21Gd954-31G4-31g*4-31g**6-31G6-31G* 6- 31G** 6-311 G** 6-311 ++G** 6-311++ (3df,2p d) cc-pvdzcc-pvtzcc-pvqc # Basis fumctions: 713141319251319253036692458115 UHF 36.133.132.634.528.228.133.927.6 26.025.524.725.325.125.0 RHF 39.536.035.437.431.5 36.830.9 29.328.828.128.6 28.4 MP2 31.628.127.029.321.520.728.720.820.118.017.415.017.515.4314.3 MP3 28.725.824.727.018.918.126.418.317.515.314.812.614.712.912.1 MP4D 27.324.723.625.917.716.825.317.116.314.113.511.313.411.610.9 MP4DQ 27.324.923.826.118.017.125.417.316.614.413.911.813.812.211.5 MP4SDTQ 27.324.623.725.817.616.725.217.016.214.113.511.413.511.711.0 MP5 26.524.123.125.217.016.124.616.415.613.513.010.912.911.3NA GVB/RO HF 23.823.223.024.514.7 24.014.314.412.612.310.511.910.810.5 CCSD 24.923.522.624.616.515.724.116.015.213.212.810.912.511.210.6 CCSD(T) 24.822.922.224.115.714.823.515.214.412.412.010.011.810.39.6 CID 26.224.723.725.918.117.525.317.517.015.014.612.714.313.012.4 CISD 26.124.723.825.918.017.425.317.516.915.014.612.914.313.212.6 QCISD 24.923.422.624.616.515.624.015.915.213.212.810.912.511.210.6 QCISD(T) 24.822.922.224.115.714.823.515.214.412.412.010.011.810.39.6 BLYP 17.015.817.217.512.712.517.012.312.211.310.79.910.910.410.1 ROBLYP 16.115.116.416.711.611.516.211.2 10.29.78.89.99.39.0 Singlet-Triplet Splittings (kcal/mole): E exp = 9.2 kcal/mole

15 Results: Energy Reaction HF/6-31FG** //HF6- 31G* MP2/6-31G** //MP2/6-31G* MP3/6-31G** //MP3/6-31G* MP4/6-31G** //MP4/6-31G* Expt. H 2 ->H*+H* 85101105106109 Li->Li*+H* 3245484958 BeH->Be*+H* 52 494750,56 BH->B*+H* 6277798082 CH*->C+H*(2) 5573757684 CH*->C+H*(4-) 626866 67 NH->N*+H* 5071727379,<85 OH*->O+H* 6796 107 FH->F*+H* 93131127128141 BH 2 *->BH+H* 8488878599-130 CH 2 ->CH*+H*( 3 B 1 ) 101109108107105,106 CH 2 ->CH*+H*( 1 A 1 ) 7089909198 NH 2 *->NH+H* 6590 102 OH 2 ->OH*+H* 86119115116126 BH 3 ->BH 2 *+H* 9010610810957-107 CH 3 *->CH 2 +H* 88110112 117 NH 3 ->NH 2 *+H* 83110108109116 CH 4 ->CH 3 *+H* 87109110 113

16 Results: Energy

17 Results: Charge Example: Chlorine atomic charge in CH 3 Cl, HF Mulliken and NPA charges ; calculated with many basis sets (at the HF/6-31G* optimized geometry).

18 Problems: BSSE Basis Set Superposition Error MoleculesMethod BSSE kcal/mol HF+HF HF/6-31+G* MP2/6-31+G* 0.96 2.16 H 2 +NH 3 HF/DZP0.65 (CH 3 COOH) 2 HF/6-31G* MP2/6-31G* 2.5 5.6

19 Problems: Size Consistency

20 Problems: UHF Instability Method E relative (Anthracene- Phenanthrene) UHF/6-31G*1.42 RHF/6-31G*6.88 MP2/6-31G**7.09 MP3/6-31G6.17 MP4(SDQ)/6-31G6.48 CISD/DZ7.49 CCSD6.32 CCSD(T)5.98

21 Problems:Variational Principle

Download ppt "Molecular Models. Methodology: Modify Wavefunction."

Similar presentations

Introduction to Computational Chemistry NSF Computational Nanotechnology and Molecular Engineering Pan-American Advanced Studies Institutes (PASI) Workshop.

Introduction to Computational Chemistry NSF Computational Nanotechnology and Molecular Engineering Pan-American Advanced Studies Institutes (PASI) Workshop.
Introduction to Møller-Plesset Perturbation Theory

Introduction to Møller-Plesset Perturbation Theory
Electron Correlation Hartree-Fock results do not agree with experiment

Electron Correlation Hartree-Fock results do not agree with experiment
Quantum Mechanics Calculations II Apr 2010 Postgrad course on Comp Chem Noel M. O’Boyle.

Quantum Mechanics Calculations II Apr 2010 Postgrad course on Comp Chem Noel M. O’Boyle.
(4C) N1 O2 O3 O4 O5 O6 H14 H13 H7 H8 H9 H10 H11 H12 (4F) N1 O2 O3 O4 O5 O6 H13 H14 H7 H8 H9 H10 H11 H12 Supplementary Figure1. Calculated structures of.

(4C) N1 O2 O3 O4 O5 O6 H14 H13 H7 H8 H9 H10 H11 H12 (4F) N1 O2 O3 O4 O5 O6 H13 H14 H7 H8 H9 H10 H11 H12 Supplementary Figure1. Calculated structures of.
Page 34 In a chemical reaction, bonds in the reactants are broken and the atoms rearrange to form new bonds in the products. Flames or heat associated.

Page 34 In a chemical reaction, bonds in the reactants are broken and the atoms rearrange to form new bonds in the products. Flames or heat associated.
Post Hartree-Fock Methods (Lecture 2)

Post Hartree-Fock Methods (Lecture 2)
ChE 452 Lecture 16 Quantum Effects In Activation Barriers 1.

ChE 452 Lecture 16 Quantum Effects In Activation Barriers 1.
20_01fig_PChem.jpg Hydrogen Atom M m r Potential Energy + Kinetic Energy R C.

20_01fig_PChem.jpg Hydrogen Atom M m r Potential Energy + Kinetic Energy R C.
Statistical Mechanics and Multi- Scale Simulation Methods ChBE 591-009 Prof. C. Heath Turner Lecture 03 Some materials adapted from Prof. Keith E. Gubbins:

Statistical Mechanics and Multi- Scale Simulation Methods ChBE Prof. C. Heath Turner Lecture 03 Some materials adapted from Prof. Keith E. Gubbins:
Bond Enthalpies Section 5.4. Introduction More Good Stuff For H 2 the thermochemical equation describing the bond enthalpy is: H 2(g) → 2H (g) ∆H θ =

Bond Enthalpies Section 5.4. Introduction More Good Stuff For H 2 the thermochemical equation describing the bond enthalpy is: H 2(g) → 2H (g) ∆H θ =
Types of Symmetry in Molecules 1. axis of symmetry (C n ) 2. plane of symmetry (  ) 3. center of symmetry (i) 4. improper axis of symmetry (S n ) “Wavefunctions.

Types of Symmetry in Molecules 1. axis of symmetry (C n ) 2. plane of symmetry (  ) 3. center of symmetry (i) 4. improper axis of symmetry (S n ) “Wavefunctions.
MO diagram for homonuclear diatomic molecules Li 2 through N 2 MO diagram for homonuclear diatomic molecules O 2 and F 2.

MO diagram for homonuclear diatomic molecules Li 2 through N 2 MO diagram for homonuclear diatomic molecules O 2 and F 2.
Chemistry 6440 / 7440 Electron Correlation Effects.

Chemistry 6440 / 7440 Electron Correlation Effects.
Electronic Structure for Excited States (multiconfigurational methods) Spiridoula Matsika.

Electronic Structure for Excited States (multiconfigurational methods) Spiridoula Matsika.
Ab Initio Molecular Orbital Theory. Ab Initio Theory n Means “from first principles;” this implies that no (few) assumptions are made, and that the method.

Ab Initio Molecular Orbital Theory. Ab Initio Theory n Means “from first principles;” this implies that no (few) assumptions are made, and that the method.
Molecular Modeling: Density Functional Theory C372 Introduction to Cheminformatics II Kelsey Forsythe.

Molecular Modeling: Density Functional Theory C372 Introduction to Cheminformatics II Kelsey Forsythe.
Calculating Molecular Properties

Calculating Molecular Properties
Computational Chemistry

Computational Chemistry
Daniel Sánchez Portal Ricardo Díez Muiño Centro de Física de Materiales Centro Mixto CSIC-UPV/EHU centro de física de materiales CFM.

Daniel Sánchez Portal Ricardo Díez Muiño Centro de Física de Materiales Centro Mixto CSIC-UPV/EHU centro de física de materiales CFM.

Similar presentations

Ads by Google