The course aims to provide an overview of the main and modern computational techniques based on the use of Quantum Mechanics. The different techniques are illustrated according to the following scheme: theoretical introduction, advantages and disadvantages, practical use. A series of practical computer exercises complete the course.
Expected learning outcomes
Students will gain knowledge of some widely used quantum modeling techniques and their possible use. They will be able to use quantum mechanical programs and graphical interfaces.
Lesson period: First semester
(In case of multiple editions, please check the period, as it may vary)
Outline of Force Fields methods. The problem of parameterization. Differences and validation of the force fields. Computational considerations. Advantages and limitations of the force fields.
Outline of optimization techniques and associated numerical problems.
Determination of the electronic structure. The Born-Oppenheimer approximation. The SCF theory. The energy of a determinant. Koopman's theorem. SCF techniques. Outline of periodic systems. Semi-empirical methods. Advantages and limitations of semiempirical methods.
The problem of electronic correlation. Determinants of excited Slater. The configuration interaction method. Outline of perturbative methods. The MPn methods.
The method of the functional Density. Background. The Kohn Sham method. Use of DFT techniques: advantages and disadvantages.
Valence Bond methods. The Generalized Valence Bond method. Advantages and limitations.
Practical considerations for ab-initio calculations. Definition of basis sets. Determination of Molecular properties. The problem of the Basis Set Superposition Error. Vibrational spectra. Determination of electrostatic potential. Orbital localization techniques.
Ab initio determination of electronic density. Introduction to Bader's analysis.
The hybrid methods QM / MM. Theory and implementation. Advantages and limitations
Conformational analysis. Systematic and random methods. Genetic algorithms. The distance geometry method.
Use of statistical thermodynamics for the determination of thermodynamic quantities with ab-initio methods.
11 afternoons where quantum mechanical calculations for molecular systems are carried out individually using standard codes, such as Gaussian or Quantum Espresso. The student will learn how to write an input file, how to read an output, notions of zmatrix, basis set, HF calculation, post-HF and DFT, thermochemistry, calculation of reaction constants and reactive potential profiles, of structures in state solid and excited electronic states. Finally the student will write an individual report on a topic of his / her choice.
Prerequisites for admission
Knowledge of mathematics and physical chemistry
Frontal lessons and use of quantum mechanical programs
- Introduction to Computational Chemistry F. Jensen - Wiley
Assessement methods and criteria
- theoretical part: The exam consists of a compulsory written test and a possible oral test. The written test requires the answer to theoretical questions. - laboratory: interview to ascertain the understanding of the work performed, documented by a written report.