Course syllabus (PDF file)

This the course page for Statistical Mechanics and Chemistry, taught by Prof. Pratyush Tiwary in Spring 2026. Relevant links, references etc. will be uploaded here. I will also upload homework/exam problems here (but likely not their solutions except those for midterms and final exam). The class will taught in-person, with recorded videos through youtube available after class. However you should try your best to attend the live classes and engage in discussions on the slack workspace if you want to make the best of this class.

What's new:

• Midterm 2 will be on April 7.

• Homework 3-4 (one combined homework) is now available (PDF file)

Lectures:

Lectures 10-11 (3/10, 3/12): Non-interacting ideal systems. Phonon gas: Inability of classical mechanics to explain heat capacity measurements, quantum statistical mechanics to the rescue. Einstein and Debye Models.

• Lecture 11 PDF notes, video (youtube link)

• Lecture 10 PDF notes, video (youtube link)

• Homework 3-4 (one combined homework - PDF file)

Lectures 8-9 (3/3, 3/5): Grand canonical ensemble and grand potential. Number fluctuations.

• Lecture 9 PDF notes, video (youtube link)

• Lecture 8 PDF notes, video (youtube link)

Lectures 7 (2/24): Same example using microcanonical and canonical ensembles. 

• Lecture 7 PDF notes, video (youtube link)

Lectures 5-6 (2/17, 2/19): Canonical ensemble. Thermodynamics from canonical ensemble. Energy fluctuations. 

• Lecture 6 PDF notes, video (youtube link)

• Lecture 5 PDF notes, video (youtube link)

Lecture 4 (2/12): Microcanonical ensemble and the principle of equal a priori probabilities. Thermodynamics from microcanonical ensemble. Why does not the energy "shell width" matter in microcanonical ensemble.  

• Lecture 4 PDF notes, video (youtube link)

• Homework 2 (PDF file)

Lectures 2-3 (2/3-2/5): Thermo refresher. Introduction to ergodic hypothesis and ensembles. Microcanonical ensemble and the principle of equal a priori probabilities.

• Lecture 3 PDF notes, audio only (youtube link)

• Lecture 2 PDF notes, video (youtube link)

Lecture 1 (1/29): An ode to Thermodynamics but why we need Statistical Mechanics. Math and Thermo refresher. 

• Watch: This Youtube clip (7 min 33 sec)

• Read this substack post

• Lecture 1 PDF notes, video (youtube link)

• Homework1 (PDF file)