Quantum-mechanical simulation of the electronic structure in solids


Instructions: Autumn 2007

Aim: to introduce modern computational chemistry software and its applications. By the end of the 'experiment', you should have experience of setting up a calculation or series of calculations to help solve a chmical problem.

Assessment: Each pairs of students will give a 15 minutes presentation (no more than 15 slides), followed by 15 minutes of questions at the end of the 2-week prokect slot. This will be assessed by the project supervisor and the supervisor of another set of projects. This should take place on the afternoon of Friday, 19th October.

Questions related to this computational experiment can be directed to Prof. Nicholas Harrison and Dr Giuseppe Mallia.


Introduction

The properties of solids depend on the electronic structure, which is related to the nature of the interaction between atoms. In this laboratory you will use a quantum-mechanical program to calculate the electronic structure of an ionic, a covalent, a molecular and a metallic crystal.


The Software: RedHat Linux, DLVisualize and CRYSTAL

Linux provides an excellent environment for numerical simulations so the first step is to reboot your computer into RedHat Linux.

The environment is not hugely dissimilar to that provided by Microsoft Windows. You will find a web browser (Mozilla) on the tool bar and under the Start Menu you will find some office tools (Writer, Math etc.) which are similar to those in Microsoft Office (Word, Excel etc.) and you may find them useful in plotting your data and writing your report.

DLVisualize is a general purpose graphical user interface for modelling. It will give you relatively easy access to a number of quantum mechanical and empirical simulation codes. In this case the interface to the code CRYSTAL.

The CRYSTAL program computes the ground state energy, electronic wave function and properties of periodic systems within Hartree Fock, density functional or various hybrid approximations, will be used.

There are web sites devoted to both DLV and CRYSTAL where you can find some additional information.

Further information about DLV

Further information about CRYSTAL


Before starting the exercises it is recommended to have a look the CRYSTAL input and output structure.
A quick tour of CRYSTAL input and output

Exercises:

    Ionic crystals

  1. MgO -- GROUPS A, B and C
    MgO geometry input
    MgO_geometry output
    Run a MgO wavefunction calculation
    Run a MgO properties calculation: 3D Charge Density
    Run a MgO properties calculation: Charge Density Slide
    Run a MgO properties calculation: Band Structure
    Run a MgO properties calculation: Density of States
    Run a MgO properties calculation: Band Structure + Density of States
    Optimise the MgO structure
    Calculate the MgO bulk modulus

  2. LiF -- GROUP A
    Create an input for LiF by setting the cell paramenter equal to 4.02 Angstom, the experimental value [4],
    and by using the basis set for Li and F

    Run a wavefunction calculation
    Run a properties calculation: 3D Charge Density
    Run a properties calculation: Charge Density Slide
    Run a properties calculation: Band Structure
    Run a properties calculation: Density of States
    Run a properties calculation: Band Structure + Density of States
    Optimise the structure
    Calculate the bulk modulus

  3. NaF -- GROUP B
    Create an input for NaF by setting the cell paramenter equal to 4.64 Angstom, the experimental value [4],
    and by using the basis set for Na and F

    Run a wavefunction calculation
    Run a properties calculation: 3D Charge Density
    Run a properties calculation: Charge Density Slide
    Run a properties calculation: Band Structure
    Run a properties calculation: Density of States
    Run a properties calculation: Band Structure + Density of States
    Optimise the structure
    Calculate the bulk modulus

  4. NaCl -- GROUP C
    Create an input for NaCl by setting the cell paramenter equal to 5.64 Angstom, the experimental value [4],
    and by using the basis set for Na and Cl

    Run a wavefunction calculation
    Run a properties calculation: 3D Charge Density
    Run a properties calculation: Charge Density Slide
    Run a properties calculation: Band Structure
    Run a properties calculation: Density of States
    Run a properties calculation: Band Structure + Density of States
    Optimise the structure
    Calculate the bulk modulus

  5. LiCl -- GROUP A, B and C -- optional
    Create an input for LiCl by setting the cell paramenter equal to 5.1396 Angstom, the experimental value [4],
    and by using the basis set for Li and Cl

    Run a wavefunction calculation
    Run a properties calculation: 3D Charge Density
    Run a properties calculation: Charge Density Slide
    Run a properties calculation: Band Structure
    Run a properties calculation: Density of States
    Run a properties calculation: Band Structure + Density of States
    Optimise the structure
    Calculate the bulk modulus

    Covalent crystals

  6. C (C.inp) -- GROUP C
    Run a wavefunction calculation
    Run a properties calculation: 3D Charge Density
    Run a properties calculation: Charge Density Slide
    Run a properties calculation: Band Structure
    Run a properties calculation: Density of States
    Run a properties calculation: Band Structure + Density of States
    Optimise the structure
    Calculate the bulk modulus

  7. Si (Si.inp) -- GROUP B
    Run a wavefunction calculation
    Run a properties calculation: 3D Charge Density
    Run a properties calculation: Charge Density Slide
    Run a properties calculation: Band Structure
    Run a properties calculation: Density of States
    Run a properties calculation: Band Structure + Density of States
    Optimise the structure
    Calculate the bulk modulus

  8. Ge (Ge.inp) -- GROUP A
    Run a wavefunction calculation
    Run a properties calculation: 3D Charge Density
    Run a properties calculation: Charge Density Slide
    Run a properties calculation: Band Structure
    Run a properties calculation: Density of States
    Run a properties calculation: Band Structure + Density of States
    Optimise the structure
    Calculate the bulk modulus

    Molecular crystal

  9. Urea - CO(NH2)2   (Urea.inp) -- GROUPS A, B and C
    Urea geometry input
    Run a wavefunction calculation
    Run a properties calculation: 3D Charge Density
    Run a properties calculation: Charge Density Slide
    Run a properties calculation: Band Structure
    Run a properties calculation: Density of States
    Run a properties calculation: Band Structure + Density of States

    Metallic crystal

  10. Be (Be.inp) -- GROUPS A, B and C
    Run a wavefunction calculation
    Run a properties calculation: 3D Charge Density
    Run a properties calculation: Charge Density Slide
    Run a properties calculation: Band Structure
    Run a properties calculation: Density of States
    Run a properties calculation: Band Structure + Density of States

Additional material

  1. "How Chemistry and Physics Meet in the Solid State" By Roald Hoffmann, Angew Chem Inr. Ed Engl 26 (1987) 846-878
  2. "Electronic Structure of Materials" by Adrian P. Sutton, Oxford Science Publications
  3. "Bonding and structrure of molecules and solids" by David Pettifor, Oxford Science Publications
  4. "Basic Solid State Chemistry" by Anthony R. West, John Wiley and Sons
  5. Notes